Name: Glossary
Creator: Peptides Explained
Published: 2026-10-20

5

503A bulks list (503A Bulks List, 503A bulk drug substances list, 503A list): A US list of raw drug substances that licensed pharmacies may use to prepare medicines for individual prescriptions, even though no approved medicine contains them. Being on the list is not an approval.; Regulation; See also: compounding, PCAC
510(k) clearance (510(k), device clearance): A US route that lets a medical device, such as a wound dressing, be sold when the FDA finds it similar to one already on the market. It is not a drug approval.; Regulation; See also: FDA

A

abscess (abscesses): A painful pocket of pus under the skin, usually caused by bacteria. It often needs to be drained by a doctor.; Safety; See also: sterile abscess, cellulitis
absolute risk (absolute risks, absolute risk reduction, absolute difference): How many people out of a group are affected, for example 8 in 100. The absolute difference between two groups is the number of people a treatment actually changes things for.; Research and evidence; See also: relative risk, number needed to treat, natural frequency
absorption enhancer (absorption enhancers, permeation enhancer, permeation enhancers, helper substance): An added substance that helps a medicine pass through a lining, such as the gut wall. SNAC in semaglutide tablets is one.; How drugs work in the body; See also: SNAC, bioavailability
abstention (abstentions, abstained): When a member of a committee takes part in a vote but chooses not to vote for or against.; Regulation; See also: PCAC
Ac-SDKP (AcSDKP, N-acetyl-seryl-aspartyl-lysyl-proline): A peptide of four amino acids that the body cuts from the start of thymosin beta-4. In animal studies it reduces inflammation and scarring. TB-500 does not contain it.; Biology; See also: thymosin beta-4, prolyl oligopeptidase
accelerated approval (accelerated approvals, accelerated approval pathway): A US route, formalised in 1992, that approves a medicine for a serious disease on an early sign of benefit, such as a shrinking tumour. Later trials must confirm a real benefit.; Regulation; See also: surrogate endpoint, confirmatory trial
accelerated assessment: A faster EU review, of up to 150 days instead of 210, for medicines of major interest to public health.; Regulation; See also: PRIME scheme, centralised procedure
acetylation (acetylated, N-acetylated, acetyl group, N-terminal acetylation, unacetylated, non-acetylated): Adding a small chemical group (an acetyl group) to a molecule. On a peptide it changes the charge and shape of the start of the chain, so it can change how the peptide works and how long it lasts.; Chemistry
acromegaly: A disease caused by too much growth hormone in adults. Hands, feet and the face slowly grow larger, and diabetes and heart problems become more common.; Biology; See also: growth hormone, IGF-1
ACTH (adrenocorticotropic hormone, corticotrophin, corticotropin): A hormone from the pituitary gland that tells the adrenal glands to make cortisol.; Biology; See also: cortisol, pituitary gland
actin (G-actin, actin filaments, actin monomers, actin-binding, actin units): A protein that forms thin threads inside cells. Cells build and take apart these threads to change shape and to move.; Biology; See also: thymosin beta-4, cytoskeleton
acute hepatitis: Inflammation of the liver that starts suddenly. Signs can include yellow skin or eyes, dark urine and feeling very unwell.; Safety; See also: jaundice
acute kidney injury (AKI, acute renal failure, kidney injury, acute kidney failure): A sudden drop in how well the kidneys work, over hours or days. Severe dehydration, for example from long-lasting vomiting or diarrhoea, is one cause.; Safety; See also: eGFR
acute pancreatitis (pancreatitis): Sudden inflammation of the pancreas. It typically causes severe, constant pain in the upper belly that can spread to the back, often with vomiting. It needs urgent medical care.; Safety
adenylate cyclase (adenylyl cyclase): The enzyme that makes the messenger cAMP inside a cell when a G protein switches it on.; Biology; See also: cAMP, G protein
adequate and well-controlled study (adequate and well-controlled studies, adequate and well-controlled investigations, adequate and well-controlled): A study built to separate the effect of a medicine from chance, the natural course of the illness, the placebo effect and biased observation. It compares with a control group and usually uses randomisation and blinding.; Research and evidence; See also: substantial evidence, randomised controlled trial
ADME: Short for absorption, distribution, metabolism and excretion: the four things the body does to a medicine.; How drugs work in the body; See also: pharmacokinetics
administrative fine (bestuurlijke boete, administrative fines): A fine that a government body such as the IGJ gives itself, without going to a criminal court.; Law; See also: IGJ
adrenaline pen (adrenaline pens, adrenaline auto-injector, adrenaline auto-injectors): A ready-to-use pen that injects adrenaline into the thigh during a severe allergic reaction. People with known severe allergies carry one.; Safety
advisory committee (advisory committees): A group of outside experts that gives a regulator advice. Its vote is a recommendation, not a decision.; Regulation; See also: PCAC, FDA
affinity (binding affinity): How tightly a molecule grips its receptor. High affinity does not by itself mean a strong effect.; How drugs work in the body; See also: intrinsic efficacy, potency
agonist (agonists, receptor agonist, receptor agonists): A substance that fits a receptor and switches it on, in the same way as the body's own messenger.; How drugs work in the body; See also: triple agonist
Aib (2-aminoisobutyric acid, α-aminoisobutyric acid, alpha-aminoisobutyric acid): An amino acid that is not used in normal human proteins. Putting it at position 8 of semaglutide protects the peptide from being cut by the enzyme DPP-4.; Chemistry; See also: DPP-4
AICAR: A small natural molecule inside cells that switches on AMPK, the cell's energy sensor. As a drug it is banned in sport.; Biology; See also: AMPK
Akt (protein kinase B, Akt signalling): A switch protein inside cells that tells them to survive and grow. Many cancers keep it switched on.; Biology; See also: integrin-linked kinase
albumin binding (albumin, serum albumin, plasma albumin, bound to albumin): Albumin is the most common protein in blood. A drug that sticks to it stays in the blood longer, because the albumin–drug pair is too big to be filtered out by the kidneys.; How drugs work in the body; See also: fatty-acid side chain
allocation concealment (concealed allocation, concealment of allocation): Keeping the next group assignment hidden from the researchers until a participant has joined, so they cannot steer particular people or animals into one group.; Research and evidence; See also: randomisation
allodynia: Pain from something that does not normally hurt, such as clothes touching the skin.; Safety; See also: dysaesthesia
allometric scaling (allometry, allometric, body-surface-area scaling, body surface area scaling, dose scaling): Adjusting a dose between species of different sizes using body weight or body surface area. In drug development it is one step towards a cautious first test dose in people, not a way to find a dose that works.; How drugs work in the body; See also: first-in-human trial, MABEL
alpha-MSH (α-MSH, alpha-melanocyte-stimulating hormone, alpha-melanocyte stimulating hormone, melanocyte-stimulating hormone): A small natural hormone made in the body from a larger protein. It controls skin and hair colour and also calms inflammation. KPV is its last three building blocks.; Biology; See also: proopiomelanocortin, melanocortin receptor
ALT (alanine transaminase, alanine aminotransferase, liver enzyme): An enzyme found mainly in the liver. A blood test for ALT is used to check the liver: a raised level can mean liver cells are being damaged.; Safety
ambulatory blood pressure monitoring (ABPM, ambulatory blood pressure, 24-hour blood pressure): Blood pressure measured automatically by a cuff worn during normal life, often every 15 to 30 minutes for a day or more.; Research and evidence; See also: systolic blood pressure
amide end (amide, free acid, free-acid form): How a peptide chain finishes. Most chains end in an acid group (a free acid); in some it is replaced by a small cap called an amide. Melanotan II has an amide end; bremelanotide has a free acid end.; Chemistry; See also: norleucine
amino acid (amino acids): A small molecule that is a building block of peptides and proteins. There are 20 standard kinds; each has an amino end, an acid end and its own side chain.; Chemistry; See also: peptide, peptide bond, protein
AMPK (AMP-activated protein kinase): An enzyme inside cells that senses how much energy is available and switches energy use up or down.; Biology
anabolic agent (anabolic agents): A substance that builds muscle, such as testosterone, related steroids and some other drugs. The anti-doping list bans them at all times, in its section S1.; Sport; See also: anabolic steroids, Prohibited List
anabolic steroids (anabolic steroid, anabolen, AAS): Man-made versions of the male hormone testosterone and related substances, used to build muscle. They are banned in sport.; Sport; See also: WADA
anaemia (anemia): Having too few red blood cells, or too little of the substance in them that carries oxygen. It can make you tired and short of breath.; Biology; See also: full blood count
analogue (analogues, analog, analogs): A lab-made molecule built to look like a natural one, usually changed so that it lasts longer or acts more strongly.; Chemistry
anamorelin (Adlumiz): A tablet that switches on the ghrelin receptor, developed for weight loss in people with lung cancer. The EU refused to approve it in 2017.; How drugs work in the body; See also: ghrelin receptor
anaphylaxis (anaphylactic reaction, anaphylactic reactions): A severe allergic reaction that affects the whole body within minutes. It can cause breathing problems and a sudden drop in blood pressure, and needs emergency care.; Safety; See also: angioedema
anastomotic leak (anastomotic leaks): A leak where two ends of the bowel were sewn or stapled back together during an operation. It is a serious complication of bowel surgery.; Biology; See also: postoperative ileus
angioedema: Swelling deep under the skin, often of the face, lips, tongue or throat. Swelling in the throat can block breathing.; Safety; See also: anaphylaxis
angiogenesis (angiogenic, pro-angiogenic, new blood vessel growth): The growth of new small blood vessels from existing ones. Healing tissue needs it, and tumours also use it to get a blood supply.; Biology; See also: VEGFR2
ANGPTL3/8 (ANGPTL3/8 complex): A pair of proteins made by the liver that slows the breakdown of fats in the blood. Lower levels go with lower triglycerides.; Biology; See also: triglycerides
animal model (animal models, disease model, disease models, injury model, injury models): An animal in which researchers create a condition, such as a cut tendon or a blocked artery, to stand in for a human disease. The model is never exactly the human disease.; Research and evidence; See also: external validity, translational research
annex (annexes): An extra part at the end of a law, often a list. It is part of the law and has the same force as the rest of it.; Law
antagonist (antagonists, receptor antagonist, receptor antagonists): A molecule that binds a receptor without switching it on, so it blocks the body's own signal.; How drugs work in the body; See also: agonist, inverse agonist
Anti-Doping-Gesetz (AntiDopG, German anti-doping law): The German law against doping in sport. It makes trading in doping substances a crime, and owning a large amount of some listed substances too.; Law; See also: nicht geringe Menge, Prohibited List
anti-drug antibodies (anti-drug antibody, antibodies against the protein): Antibodies that the immune system makes against a medicine. They can make the medicine work less well or cause reactions.; How drugs work in the body; See also: immunogenicity
antibody (antibodies): A protein that the immune system makes to recognise something foreign, such as a germ or a drug, and mark it for removal.; Biology; See also: immune system, anti-drug antibodies
anticoagulant (anticoagulants, blood thinner, blood thinners): A medicine that makes blood take longer to clot, to prevent dangerous clots. People who take one bruise and bleed more easily.; How drugs work in the body; See also: INR
antiemetic (antiemetics, anti-emetic, anti-sickness medicine, anti-nausea medicine): A medicine that prevents or eases feeling sick and vomiting.; How drugs work in the body
antiretroviral therapy (antiretroviral treatment, antiretroviral drugs, HIV medicines, HIV treatment): A combination of medicines that keeps HIV under control. Some older HIV medicines changed where the body stores fat.; How drugs work in the body; See also: HIV, lipodystrophy
anxiolytic (anxiolytics, anti-anxiety medicine): A medicine that reduces anxiety.; How drugs work in the body; See also: benzodiazepine
apnoea–hypopnoea index (AHI, apnoea-hypopnoea index, apnea-hypopnea index): The number of times per hour of sleep that breathing stops or becomes very shallow. It is used to measure how severe sleep apnoea is.; Research and evidence; See also: obstructive sleep apnoea
aPTT (activated partial thromboplastin time, APTT): A blood test that measures how long blood plasma takes to clot. A shorter time can mean a higher risk of clots; a longer time can mean a higher risk of bleeding.; Safety
arrhythmia (arrhythmias, cardiac arrhythmias, heart rhythm disorder, irregular heartbeat): A heartbeat that is too fast, too slow or irregular.; Safety; See also: atrial fibrillation, tachycardia
arthralgia (joint pain, joint pains): Pain in one or more joints, without visible damage to the joint.; Biology; See also: myalgia
Arzneimittelgesetz (AMG, German Medicines Act): The German Medicines Act. It says what counts as a medicine, which medicines need a licence, and which acts are crimes.; Law; See also: Fertigarzneimittel, marketing authorisation
aseptic technique (aseptic, asepsis): A set of habits that keeps sterile things free of germs while you use them, such as clean hands, a new needle and not touching the needle or the vial top.; Safety; See also: sterile, stopper
ATP synthase (ecto-ATP synthase, cell-surface ATP synthase): An enzyme that makes ATP, the molecule cells use to store energy. A small amount also sits on the outside of some cells, where it can act as a signal.; Biology
atrial fibrillation (AF): A common irregular heartbeat in which the upper chambers of the heart quiver instead of beating in rhythm. It raises the risk of stroke.; Safety; See also: arrhythmia
authorisation under exceptional circumstances (authorised under exceptional circumstances, authorised under 'exceptional circumstances'): An EU licence for a medicine whose full benefits and risks cannot be shown, for example because the disease is very rare. The regulator reviews it every year.; Regulation; See also: conditional marketing authorisation, orphan medicine
autoimmune disease (autoimmune diseases, autoimmune): An illness in which the immune system attacks the body's own tissues. Type 1 diabetes is one example.; Biology; See also: immune system
autoinjector (autoinjector pen, autoinjectors): A pen with a fixed, pre-filled amount of medicine and a hidden needle. Pressed against the skin, it injects the dose by itself.; How drugs work in the body; See also: subcutaneous

B

β-arrestin (beta-arrestin, β-arrestins, beta-arrestins, β-arrestin1): A protein inside cells that binds to an activated receptor. It helps switch the receptor off and pull it into the cell.; Biology; See also: receptor internalisation, biased agonism
bacteriostatic water (bacteriostatic water for injection): Sterile water for injection with a preservative (benzyl alcohol) that slows the growth of bacteria. It comes in a container that may be opened more than once.; Safety; See also: sterile water for injection, preservative
Barth syndrome (BTHS): A rare inherited disease, mostly in boys and men. A faulty gene changes cardiolipin, which can weaken the heart and muscles and cause tiredness.; Biology; See also: cardiolipin, mitochondria
baseline (baseline test, baseline value, baseline result): A first measurement taken at the start, before anything changes. Later results are compared with it.; Research and evidence
batch number (batch numbers, lot number, lot numbers): A code on a medicine that shows which production run it came from. It lets a maker or regulator trace and recall a faulty batch.; Regulation; See also: falsified medicine
BDNF (brain-derived neurotrophic factor): A growth factor in the brain that helps nerve cells survive and form new connections.; Biology
benzodiazepine (benzodiazepines): A group of anxiety and sleep medicines, such as diazepam. They work quickly but can cause drowsiness and dependence.; How drugs work in the body; See also: anxiolytic
benzyl alcohol: A preservative that stops germs growing in some multi-dose medicines. It can be dangerous for newborn babies.; How drugs work in the body; See also: preservative
beta-3 receptor (beta-3 adrenergic receptor, β3-adrenergic receptor): A receptor on fat cells that adrenaline switches on to release stored fat.; Biology; See also: receptor, lipolysis
BfArM (Bundesinstitut für Arzneimittel und Medizinprodukte): The German federal institute for medicines and medical devices. It runs an online portal where patients and health workers can report side effects.; Regulation
biased agonism (biased agonist, signalling bias, signaling bias): A receptor can pass on a signal along more than one route inside the cell. A biased drug switches on some of these routes more than others.; How drugs work in the body; See also: β-arrestin, cAMP
BIG register (BIG-register, BIG registration): The Dutch public register of licensed health professionals, such as doctors and pharmacists. Only a doctor in this register may sign a doctor's declaration.; Law; See also: Wet BIG, named-patient route
bioavailability (absolute bioavailability, oral bioavailability, bioavailable): The share of a dose that reaches the bloodstream unchanged, compared with an injection straight into a vein.; How drugs work in the body; See also: first-pass metabolism, pharmacokinetics
biological product (biological products, biological medicine, biologic, biologics): In US law, a medicine such as a protein, vaccine or blood product. Any chain of more than 40 amino acids counts as a protein, so some large peptides are regulated as biological products.; Regulation; See also: Biologics License Application, protein
Biologics License Application (BLA): The formal request a company sends to the US FDA to approve a biological medicine. The FDA then reviews the data before it decides.; Regulation
biopsy (biopsies, liver biopsy, liver biopsies): Taking a tiny piece of tissue, for example with a needle from the liver, to look at it under a microscope.; Research and evidence; See also: liver fibrosis
blinding (blinded, double-blind, double blind, double blinding, blinded outcome assessment, single-blind): Keeping participants, researchers or the people who measure the results from knowing who got the treatment. Expectations then cannot colour what is reported or measured.; Research and evidence; See also: placebo, open-label
blood-borne virus (blood-borne viruses, bloodborne virus, bloodborne viruses): A virus that can pass from one person to another through blood, for example on a shared needle. The main ones are HIV, hepatitis B and hepatitis C.; Safety; See also: hepatitis B and C, needle-stick injury
blood-brain barrier (blood–brain barrier, blood brain barrier): The tight wall of cells around the brain's blood vessels. It keeps most large molecules, including most peptides, out of the brain.; Biology; See also: circumventricular organs
BMI (body-mass index, body mass index): Body mass index: your weight in kilograms divided by your height in metres squared. A BMI of 30 or more counts as obesity.; Biology
boxed warning (black box warning): The strongest warning on a US medicine label, printed in a box at the top.; Regulation
brown fat (brown adipose tissue, brown-fat): A kind of body fat that burns energy to make heat, instead of storing it.; Biology
brush border (brush-border enzymes): The surface of the cells lining the small intestine, covered with tiny projections and enzymes that finish digesting protein into amino acids.; Biology; See also: tight junction
bulk drug substance (bulk drug substances, active pharmaceutical ingredient, active pharmaceutical ingredients): The raw active ingredient, often a powder, from which a pharmacy or factory makes a medicine.; Regulation; See also: 503A bulks list, compounding
Bundesgesetzblatt (BGBl, federal law gazette): The official German journal in which federal laws and treaties are published. Germany publishes each year's doping list there.; Law; See also: Anti-Doping-Gesetz

C

C-terminal amide (amidated, C-terminally amidated, amidation): The end of a peptide chain finished with an amide group (–NH2) instead of an acid group. Many natural peptide hormones end this way.; Chemistry
C-terminus (C-termini, acid end): The end of a peptide chain, where a free acid group sits unless it has been changed.; Chemistry; See also: N-terminus, C-terminal amide
cAMP (cyclic AMP, cyclic adenosine monophosphate): A small messenger molecule inside cells. When some receptors are switched on, cAMP levels rise and pass the signal on to the cell's machinery.; Biology
carcinogenicity study (carcinogenicity studies, carcinogenicity testing): A long-term animal study that tests whether a substance causes tumours or makes them grow. Regulators usually ask for one when people will use a medicine for six months or more.; Safety; See also: genotoxicity
cardiolipin (cardiolipins): A fat molecule found almost only in the inner wall of mitochondria. It helps the parts that make energy work together.; Biology; See also: mitochondria, inner mitochondrial membrane, Barth syndrome
cardiovascular disease (heart disease, heart and blood vessel disease): Disease of the heart or blood vessels, such as a past heart attack, angina, heart failure or a stroke.; Safety; See also: hypertension
cardiovascular outcomes trial (cardiovascular outcomes trials, CVOT, outcomes trial): A large, long trial that counts real events such as heart attacks, strokes and deaths, instead of only measuring blood sugar or weight.; Research and evidence; See also: MACE
carpal tunnel syndrome (carpal tunnel): Numbness, tingling or pain in the hand and fingers when a nerve at the wrist is squeezed, for example by swollen tissue.; Biology; See also: arthralgia, paraesthesia
case report (case reports): A published description of what happened to one patient. It can raise an alarm, but it cannot show what caused the problem.; Research and evidence; See also: case series
case series (case-series, case series report): A report on a group of patients who all had the same treatment, with no comparison group. It can raise questions but cannot show that the treatment caused the result.; Research and evidence
case-control study (case-control studies): A study that starts with people who have a disease (cases) and compares them with similar people who do not (controls), looking back at what they were exposed to.; Research and evidence; See also: observational study
castrate level (castrate levels, castrate concentrations): A testosterone level as low as after removal of the testes. Some prostate cancer treatments aim for it on purpose.; Biology; See also: GnRH
catalyst (catalysts, metal catalyst, metal catalysts): A substance that speeds up a chemical reaction without being used up. Some catalysts used to make peptides contain metals, so leftover metal must be tested for.; Chemistry; See also: impurity
Category 2 (category 2): An FDA list of substances nominated for pharmacy compounding that the agency said may present significant safety risks. The FDA said it may take action against pharmacies that compound them.; Regulation; See also: 503A bulks list
CBG (CBG-MEB, Medicines Evaluation Board, College ter Beoordeling van Geneesmiddelen): The Dutch Medicines Evaluation Board. It decides which medicines may be sold in the Netherlands, and works with the EMA on EU decisions.; Regulation; See also: EMA, medicines regulator
CCMO (Centrale Commissie Mensgebonden Onderzoek, Central Committee on Research Involving Human Subjects): The Dutch central committee for research in people. It supervises the ethics committees and reviews some studies itself.; Regulation; See also: METC
CD36: A protein on the surface of heart, blood-vessel and other cells. In rat hearts, hexarelin attached to it.; Biology; See also: receptor
CDC (Centers for Disease Control and Prevention, US Centers for Disease Control and Prevention): The US national public health agency (Centers for Disease Control and Prevention). It gives advice on how to prevent infections, for example with safe injections.; Regulation
cell membrane (cell membranes): The thin, oily outer wall of a cell. Small, fat-loving molecules pass through it; large, water-loving ones mostly do not.; Biology; See also: hydrophilic, receptor
cellulitis (wondroos): A bacterial infection of the deeper layers of the skin. The skin becomes red, hot, swollen and painful, and it needs antibiotics. (Doctors in the Netherlands often call a similar infection wondroos.); Safety; See also: abscess, sepsis, lymphangitis
centralised procedure (central procedure, centralised authorisation): The EU route to approve a medicine for all EU countries at once. The EMA assesses it and the European Commission decides.; Regulation; See also: EMA, marketing authorisation
certificate of analysis (certificates of analysis, CoA): A document from a maker that lists the tests done on one batch of a product and the results. It is only as good as the tests it includes.; Safety
CHMP (Committee for Medicinal Products for Human Use): The European Medicines Agency's expert committee that assesses applications for human medicines and advises whether the EU should authorise them.; Regulation; See also: EMA, marketing authorisation
cholesterol: A fatty substance carried in the blood. Too much of some kinds raises the risk of heart attacks and strokes.; Biology
circumventricular organs (circumventricular organ): Small areas of the brain where the blood-brain barrier is open, so substances in the blood can reach brain cells there.; Biology; See also: blood-brain barrier
citation laundering (citation distortion, citation bias, citation amplification): Our name for a claim gaining authority by being cited from paper to paper, often review to review, without new data, until a guess reads like a fact.; Research and evidence; See also: narrative review, independent replication
clamp study (hyperglycaemic clamp, hyperglycemic clamp, euglycaemic clamp, euglycemic clamp, hyperinsulinaemic euglycaemic clamp, clamp disposition index): A detailed test in which blood sugar is held at a fixed level with a drip. Researchers then measure how much insulin the body makes, or how much sugar it takes up.; Research and evidence; See also: insulin sensitivity
Class C drug (Class C drugs, Class C): The lowest of three groups of controlled drugs in the UK. It includes some hormones, such as growth hormone, but none of the peptides on this site.; Law; See also: Misuse of Drugs Act
clearance (drug clearance, renal clearance): How quickly the body removes a medicine, measured as the volume of plasma (the liquid part of the blood) cleared of it per unit of time, for example per hour.; How drugs work in the body; See also: half-life, glomerulus
clenbuterol: A medicine that opens the airways. Some countries use it for asthma, and vets use it in horses. It is misused to lose fat and build muscle, and it is banned in sport.; How drugs work in the body; See also: anabolic agent
clinical endpoint (clinical endpoints, clinical outcome, clinical outcomes, hard endpoint, hard endpoints): An outcome that matters to the patient directly: living longer, avoiding a heart attack, walking again, feeling better.; Research and evidence; See also: surrogate endpoint
clinical trial (clinical trials, human trial, human trials): A planned study in people that tests whether a treatment works and what harm it does. Large trials compare it with a dummy treatment or another medicine.; Research and evidence; See also: randomised controlled trial, trial phase, placebo
Clinical Trials Regulation (Regulation 536/2014, Regulation (EU) No 536/2014): The EU law on testing medicines in people. It sets rules for approval, consent and openness, and has applied since 31 January 2022.; Law; See also: CTIS, clinical trial, informed consent
ClinicalTrials.gov: A public list of clinical trials, run by the US National Library of Medicine. Trials from many countries post their plan there before they start, and some post their results.; Research and evidence; See also: pre-registration, CTIS
coenzyme (coenzymes, co-substrate): A small helper molecule that an enzyme needs to do its job. Many coenzymes are made from vitamins.; Biology; See also: enzyme, NAD+
cohort study (cohort studies, health-record study, health-record studies): A study that follows groups of people who already use different treatments, without assigning treatments at random. Other differences between the groups can distort the result.; Research and evidence
cold chain: Keeping a medicine cold at every step, from the factory to the person who uses it. If one step gets too warm or freezes, the medicine can be damaged.; Safety; See also: freeze-drying
collagen (collagens): The main building protein of skin, tendons and scars. It gives tissue its strength.; Biology; See also: fibroblast
combined lifestyle intervention (GLI, gecombineerde leefstijlinterventie): A Dutch lifestyle programme for people with overweight or obesity, with a focus on things like physical activity and diet. Dutch guidelines put it first, before obesity medicines are considered.; Regulation
comet assay (comet test): A lab test for broken DNA in single cells. Under the microscope, damaged DNA trails behind the cell like the tail of a comet.; Biology; See also: genotoxicity
comparator (comparators): What a new treatment is compared with in a trial: a dummy treatment (placebo), another medicine or no treatment. The choice can make a new medicine look better or worse.; Research and evidence; See also: placebo
compassionate use (compassionate-use, compassionate grounds): Giving an unapproved treatment to a seriously ill patient outside a trial, because other treatments have not worked. It is not a test of whether the treatment works.; Regulation
compounding (pharmacy compounding, compounded, compounding pharmacy, compounding pharmacies): When a pharmacy prepares a medicine itself for a particular patient, instead of supplying a factory-made, approved product. Compounded medicines are not checked by a regulator before use.; Regulation; See also: 503A bulks list
condensation (condensation reaction): A chemical reaction that joins two molecules and gives off a small molecule, usually water. Joining amino acids into a chain is a condensation.; Chemistry; See also: peptide bond, hydrolysis
conditional marketing authorisation (conditional marketing authorisations, conditional authorisation, conditional approval): An EU licence for a medicine that meets an unmet need, granted on less complete data. It lasts one year at a time, and the company must deliver the missing studies.; Regulation; See also: marketing authorisation, authorisation under exceptional circumstances
conditioned taste aversion (taste aversion, conditioned taste aversions): When an animal learns to avoid a taste it had just before feeling ill. Researchers use it as a sign that a drug makes animals feel sick.; How drugs work in the body
conference abstract (conference abstracts, meeting abstract, meeting abstracts): A short summary of a study, often only a few hundred words, presented at a scientific meeting. It usually leaves out the methods and full results, so readers cannot check the study properly.; Research and evidence
confidence interval (confidence intervals, 95% confidence interval, 95% CI): The range of values that are reasonably compatible with a study's data. If the range for a difference between two groups includes zero, the study cannot rule out that there is no difference.; Research and evidence
confirmatory trial (confirmatory trials, confirmatory study, confirmatory studies): A trial done after an early approval to check that a medicine really helps patients, for example that they live longer.; Research and evidence; See also: accelerated approval, surrogate endpoint
conflict of interest (conflicts of interest, competing interest, competing interests, COI, financial conflict of interest, financial conflicts of interest): A situation in which a researcher, author or adviser could gain, for example money or reputation, from a particular result. It does not make the result false, but it calls for independent checks.; Research and evidence; See also: study sponsor, key opinion leader
confounding (confounder, confounders, confounding factor, confounding factors): When a third factor affects both who gets a treatment and the outcome, so the treatment looks as if it caused something it did not. Healthier people choosing a pill is a common example.; Research and evidence; See also: observational study, randomisation
constipation (constipated): Pooing less often than usual, or finding it hard to poo.; Safety
contaminated source (contaminated product): In anti-doping rules, a product or food with a banned substance that its label does not mention. It can lower a ban only in rare cases.; Sport; See also: strict liability
contraindication (contraindications, contraindicated): A situation in which a medicine must not be used because the risk is too high, such as pregnancy or a certain illness. Authorised medicines list them on the label.; How drugs work in the body
control group (control groups, comparison group, comparison groups): The group in a study that does not get the treatment being tested, or gets a placebo or another treatment. Without it you cannot tell what would have happened anyway.; Research and evidence; See also: placebo, randomisation
conviction on indictment (on indictment): In the UK, a conviction after the more serious kind of criminal trial, usually in the Crown Court. Higher penalties are possible than in a magistrates' court.; Law
cornea (corneal, corneas): The clear front window of the eye. Small wounds on its surface usually heal within days.; Biology; See also: neurotrophic keratopathy
corticosteroid (corticosteroids, steroid injection, steroid injections, steroid replacement): A medicine that copies cortisol, a stress hormone the body makes. It calms inflammation and the immune system. People often call it a steroid, but it is not the muscle-building kind.; How drugs work in the body; See also: anabolic steroids, inflammation
cortisol: A stress hormone made by the adrenal glands. Too much for a long time can raise blood sugar and blood pressure.; Biology; See also: ACTH
CosIng: The European Commission's public database of cosmetic ingredients and the rules that apply to them.; Regulation; See also: cosmetic product
cosmetic product (cosmetic, cosmetics, cosmetic ingredient): In EU law, a product put on the outside of the body, such as skin, hair or lips, to clean, protect or change its look. Anything injected is not a cosmetic.; Law; See also: CosIng
Court of Justice of the European Union (CJEU, EU Court of Justice, European Court of Justice, Court of Justice): The highest court for EU law, in Luxembourg. When a national court asks it what an EU rule means, its answer binds courts in every EU country.; Law
covalent bond (covalent bonds, covalently, covalent): A strong chemical bond in which two atoms share electrons. Unlike loose binding, it does not simply let go again.; Chemistry; See also: maleimide
creatine kinase (CK, CPK, creatine phosphokinase): A protein inside muscle cells. When muscle is damaged it leaks into the blood, so a blood test for it shows muscle damage.; Biology; See also: rhabdomyolysis
creatinine: A waste product from muscles that the kidneys remove from the blood. Doctors measure it to check how well the kidneys work: a high level usually means the kidneys are not clearing it well.; Safety
crossover trial (crossover design, crossover study, randomised crossover): A trial in which each person receives both the treatment and the comparison (often a placebo), one after the other in random order, so they act as their own control.; Research and evidence; See also: placebo
cryo-electron microscopy (cryo-EM): A method that freezes molecules and images them with electrons, to show their three-dimensional shape in fine detail.; Chemistry
CT scan (CT scans, computed tomography): A scan that uses X-rays and a computer to make pictures of slices through the body. It can measure how much fat lies around the organs.; Research and evidence; See also: visceral fat
CTIS (Clinical Trials Information System): The EU's online system for clinical trials. Companies apply through it, and the public part lets anyone search for trials in the EU.; Regulation; See also: Clinical Trials Regulation
cyclic peptide (cyclic peptides, ring-shaped peptide, ring-shaped peptides, cyclisation, cyclization): A peptide whose chain is closed into a ring. Rings have no loose ends for some enzymes and a more rigid shape, so they often last longer.; Chemistry; See also: disulfide bond
CYP3A4: A liver enzyme that breaks down many medicines. Other drugs that block or speed it up can change how much of a medicine stays in the body.; How drugs work in the body; See also: first-pass metabolism
cytochrome P450 (CYP450, cytochrome P450 enzymes): A family of enzymes, mostly in the liver, that break down many medicines. Anything that changes them can make other medicines stronger or weaker.; How drugs work in the body
cytokine (cytokines, pro-inflammatory cytokine, pro-inflammatory cytokines, proinflammatory cytokines): A small signalling protein that immune cells release to start or spread inflammation. Examples are TNF-α and interleukin-1β.; Biology; See also: NF-κB
cytokine storm (cytokine release syndrome, cytokine-release syndrome): A sudden flood of immune signalling molecules that causes fever, low blood pressure and organ damage. It can be life-threatening.; Safety; See also: cytokine, T cell
cytoskeleton (actin cytoskeleton): The network of protein threads inside a cell. It gives the cell its shape and lets it crawl and divide.; Biology; See also: actin

D

D-amino acid (D-amino acids, D-form, L-form, mirror-image amino acid, mirror-image amino acids): The mirror-image form of an amino acid. The body builds its proteins from the other form (L); enzymes that fit L-chains often cannot cut at a D-amino acid.; Chemistry; See also: racemisation, protease
dalton (daltons, kilodalton, kilodaltons): The unit for the mass of a molecule. One dalton is roughly the mass of one hydrogen atom.; Chemistry
debarment (debarred, debarring, debarment order): A US ban on a person working for any company that has, or is seeking, approval for a medicine, imposed by the FDA after certain crimes.; Law; See also: unapproved new drug
dehydration (dehydrated): When the body loses more water than it takes in. Signs are thirst, dark urine, passing little urine, dizziness and tiredness.; Safety; See also: diarrhoea
deletion sequence (deletion sequences, truncated sequence, truncated sequences): A faulty copy of a peptide that misses one or more of its building blocks, or stops too early (a truncated sequence). It forms when a step in making the peptide does not finish.; Chemistry; See also: impurity
dendritic cell (dendritic cells): An immune cell that picks up pieces of germs and shows them to T cells, so the immune system knows what to attack.; Biology; See also: T cell, toll-like receptor
dermatologist (dermatologists): A doctor who specialises in the skin, hair and nails, including moles and skin cancer.; Safety; See also: mole (naevus), dermoscopy
dermis (epidermis): The skin has two main layers: the thin outer epidermis, and the thicker dermis below it, which holds collagen, blood vessels and nerves.; Biology; See also: stratum corneum, collagen
dermoscopy (dermatoscopy, dermatoscope, dermoscope, videodermoscopy): Looking at a mole through a lit magnifying lens, often with photos, so a doctor can see patterns that the eye alone misses and compare them over time.; Safety; See also: mole (naevus)
desensitisation (desensitization, desensitised, desensitized, desensitizes, receptor desensitisation, desensitises, desensitise): A cell's response to a signal gets weaker when the signal goes on and on. Often the cell pulls receptors off its surface or switches them off.; Biology; See also: functional antagonism, receptor internalisation
diabetic foot ulcer (diabetic foot ulcers, diabetic ulcer, diabetic ulcers, neuropathic ulcer): An open sore on the foot of someone with diabetes. It often heals slowly because nerves and blood flow are damaged.; Biology; See also: venous leg ulcer
diabetic ketoacidosis (DKA, ketoacidosis): A dangerous condition in which a lack of insulin lets ketones build up and make the blood acidic. It needs emergency treatment.; Safety; See also: ketones
diabetic retinopathy (retinopathy, diabetic eye disease): Damage to the small blood vessels at the back of the eye caused by years of high blood sugar. It can lead to bleeding in the eye and loss of sight.; Safety; See also: HbA1c
diarrhoea (diarrhea): Loose or watery poo, more often than usual. It can make you lose a lot of water.; Safety; See also: dehydration
dietary supplement (dietary supplements, food supplement, food supplements): A product swallowed to add nutrients, such as vitamins, to the diet. In the US and EU it is regulated as a food, not as a medicine.; Law; See also: new dietary ingredient
dihexa: A lab-made molecule built from a piece of the hormone angiotensin IV. It has been studied in animals for memory.; How drugs work in the body
directive (EU directive, directives): A type of EU law that tells every EU country what result to reach. Each country then writes the rules into its own national law.; Law; See also: EU regulation
Directive 65/65/EEC (Directive 65/65, 65/65/EEC): The first medicines law of the European Economic Community, of 26 January 1965. It said no ready-made medicine may be sold without a licence based on test results. Directive 2001/83/EC replaced it.; Law; See also: marketing authorisation, directive
disulfide bond (disulfide bonds, disulphide bond, disulphide bonds, sulfur bridge, sulfur bridges, disulfide-linked): A strong link between two sulfur atoms, usually from two cysteine amino acids. It can close a chain into a ring or tie two chains together.; Chemistry; See also: cyclic peptide, tertiary structure
docket (dockets, public docket): A public online file where a US agency posts the papers for a decision. Anyone can read them and send in comments.; Regulation; See also: Federal Register
dopamine (dopaminergic): A chemical messenger between nerve cells. It plays a part in motivation, reward and movement.; Biology; See also: medial preoptic area
Dopingautoriteit (Dutch Doping Authority, Doping Authority Netherlands): The Dutch national anti-doping organisation. It tests athletes, and gives information about the health effects of doping.; Sport; See also: WADA
dose–response relationship (dose-response, dose–response, dose-response relationship): The pattern in which a larger dose gives a larger effect, up to a limit. Finding this pattern is one sign that the substance itself causes the effect.; Research and evidence
DPP-4 (dipeptidyl peptidase-4, dipeptidyl peptidase 4, DPP-IV): An enzyme in the blood and gut wall that cuts the first two building blocks off GLP-1. This switches natural GLP-1 off within a couple of minutes.; Biology; See also: GLP-1, Aib
drug affinity complex (DAC, with DAC, Drug Affinity Complex): A chemical hook added to a peptide so that it bonds to albumin, a protein in the blood. It was designed to keep the peptide in the blood for days.; Chemistry; See also: maleimide, albumin binding, half-life
drug lag (drug-lag): The delay before a new medicine becomes available in one country compared with others, or its absence there. Strict or slow approval rules are one possible cause.; Regulation; See also: marketing authorisation
drug shortage list (shortage list, FDA drug shortage list): The FDA's list of medicines that are in short supply in the US. While a medicine is on it, US law allows more compounding of copies.; Regulation; See also: compounding, outsourcing facility
dry eye disease (dry eye, severe dry eye): A condition in which the eyes make too few tears, or the tears dry too quickly. It causes discomfort and can damage the surface of the eye.; Biology
DSS colitis (dextran sodium sulfate colitis, DSS-induced colitis, TNBS colitis, chemically induced colitis): A way of giving mice or rats a bowel inflammation on purpose, usually by putting a chemical (such as dextran sodium sulfate) in their drinking water, so that treatments can be tested.; Research and evidence; See also: inflammatory bowel disease
dual agonist (dual agonists, dual receptor agonist, co-agonist, co-agonists, co-agonism): One drug molecule that switches on two different receptors. Tirzepatide switches on both the GIP receptor and the GLP-1 receptor.; How drugs work in the body; See also: GIP receptor, GLP-1 receptor agonist
dulaglutide (Trulicity): A GLP-1 receptor agonist injected once a week, authorised for type 2 diabetes. It was the comparison medicine in the SURPASS-CVOT trial of tirzepatide.; How drugs work in the body; See also: GLP-1 receptor agonist
DXA scan (DXA, DEXA, dual-energy X-ray absorptiometry): A low-dose X-ray scan that measures how much of the body is fat, lean tissue and bone.; Biology; See also: lean mass
dysaesthesia (dysesthesia, dysaesthesias, dysesthesias): An unpleasant, abnormal feeling in the skin, such as burning, tingling or soreness, without an obvious cause.; Safety; See also: allodynia, hyperaesthesia
dysplastic naevus (dysplastic naevi, dysplastic nevus, dysplastic nevi, atypical mole, atypical moles): A mole whose cells look abnormal under the microscope. It is not cancer, but people with many of them have a higher risk of melanoma.; Biology; See also: mole (naevus), melanoma, melanoma in situ

E

eating disorder (eating disorders, anorexia nervosa, atypical anorexia): A mental illness in which eating, weight or body shape take over a person's thoughts and behaviour, for example by eating far too little or by binge eating.; Biology
Economic Offences Act (Wet op de economische delicten, WED): A Dutch law that makes breaches of certain other laws, such as parts of the Medicines Act, into criminal offences. Done on purpose, they count as crimes.; Law; See also: Geneesmiddelenwet
eczema: A skin condition that makes patches of skin dry, red, itchy and sometimes cracked.; Biology
EEA (European Economic Area): The European Economic Area: the EU countries plus Norway, Iceland and Liechtenstein. They share the EU rules on medicines.; Regulation
effect size (effect sizes, size of the effect): How big a difference a treatment makes, for example how many kilograms or how many fewer heart attacks. It is a different question from whether the difference could be chance.; Research and evidence; See also: p-value, confidence interval
efficacy: How well a medicine does what it is meant to do, as shown in trials. In receptor science it can also mean how strongly a molecule switches its receptor on.; Research and evidence; See also: intrinsic efficacy, randomised controlled trial
EFSA (European Food Safety Authority): The EU agency that checks the safety of foods and food ingredients. It gives advice; the European Commission decides.; Regulation; See also: novel food
eGFR (estimated glomerular filtration rate): A number, calculated from a blood test, that shows how well the kidneys filter the blood. A lower eGFR means weaker kidney function.; Research and evidence
EGR-1 (egr-1, early growth response 1, early growth response gene 1): A gene that cells switch on within minutes of injury or stimulation. Its protein then switches on other genes involved in repair and growth.; Biology
eigen risico (deductible, compulsory deductible): The part of your health care costs that you pay yourself each year in the Netherlands before your basic insurance pays. GP care does not count towards it; blood tests at a lab and hospital care do.; Law; See also: huisarts
ejection fraction (left ventricular ejection fraction, LVEF): The share of blood the main pumping chamber of the heart pushes out with each beat. A low value means the heart pumps weakly.; Biology; See also: inotropic effect
ELISA: A common lab test that uses antibodies to measure a substance in blood. It can give wrong results if the antibodies also stick to other molecules.; Research and evidence; See also: mass spectrometry
EMA (European Medicines Agency): The European Medicines Agency. It checks medicines for the whole EU and advises whether they should be approved.; Regulation; See also: medicines regulator, CBG
Embase: A large database of published medical and drug research. Reviewers search it together with PubMed so that they miss fewer studies.; Research and evidence; See also: PubMed
embryo–fetal study (embryo-fetal study, embryo–fetal studies, embryo-fetal studies): An animal study in which pregnant animals receive a substance, and the unborn young are then checked for death, poor growth or birth defects. It does not test fertility or development after birth.; Safety
emideltide (DSIP, delta sleep-inducing peptide): A lab-made copy of a small peptide first described in 1977 as delta sleep-inducing peptide (DSIP). It is not approved as a medicine in the EU, the UK or the US.; How drugs work in the body; See also: PCAC
endothelium (endothelial, endothelial cells, endothelial cell, vessel lining): The thin layer of cells that lines the inside of every blood vessel. These cells release signals, such as nitric oxide, that widen the vessel and help new vessels grow.; Biology; See also: nitric oxide, eNOS
endotoxin (endotoxins, bacterial endotoxin, bacterial endotoxins): A toxic part of the outer wall of certain bacteria. It can survive sterilisation and causes fever or shock if injected, so injectable products must be tested for it.; Safety
enema (enemas): A liquid that is put into the lower bowel through the anus. Some medicines for bowel disease are given this way.; How drugs work in the body
energy expenditure (energy use, calories burned): The amount of energy the body uses in a day: for keeping warm, breathing, digesting food and moving.; Biology
enkephalin (enkephalins, leu-enkephalin): A small natural opioid made by the body that damps down pain and stress signals. Enzymes in the blood break it down quickly.; Biology
eNOS (endothelial nitric oxide synthase): The enzyme in the inner lining of blood vessels that makes nitric oxide.; Biology; See also: nitric oxide
enzyme (enzymes): A protein that speeds up a chemical reaction in the body. When cells are damaged, some enzymes leak into the blood, where a blood test can measure them.; Biology; See also: liver tests
eosinophilia (eosinophil count, eosinophils): A raised number of eosinophils, a type of white blood cell that takes part in allergies and some infections. A blood count shows it.; Biology; See also: full blood count
epicardium (epicardial): The thin outer layer of the heart. In the embryo, some of its cells help to build the heart's blood vessels.; Biology
epidermolysis bullosa: A rare inherited disease in which the skin is so fragile that it blisters and tears after light rubbing.; Biology
epithalamin (epithalamine): An extract made from the pineal glands of cattle and used in Russia. Epitalon was designed as a lab-made copy of one small part of it.; How drugs work in the body; See also: pineal gland
epithelial-mesenchymal transition (EMT): A change in which cells that normally sit tightly together in a layer loosen and start to crawl. Wound repair uses it, and so do cancers that spread.; Biology; See also: metastasis
erectile dysfunction (erection problems): When a man often cannot get or keep an erection firm enough for sex.; Biology; See also: PDE5 inhibitor, priapism
eruptive naevi (eruptive nevi, eruptive moles, eruptive melanocytic naevi, eruptive melanocytic nevi): Many new moles that appear within a short time, sometimes weeks. They have been linked to some medicines, illnesses and tanning peptides.; Biology; See also: mole (naevus), dysplastic naevus
erythropoietic protoporphyria (EPP): A rare inherited disease in which a substance builds up in the skin and reacts to light. Even short exposure to light can cause severe burning pain.; Biology; See also: authorisation under exceptional circumstances
EU common logo (common logo, EU logo, European logo): The logo that legal online sellers of medicines in the EU must show. Clicking it should lead to a government list where the seller is registered.; Regulation; See also: falsified medicine
EU regulation (EU regulations): A type of EU law that applies directly in every EU country, without a national law in between.; Law; See also: directive
evaluator-blinded (evaluator blinded, assessor-blinded, assessor blinded): A trial in which the people who judge the results do not know who got which treatment. The patients and the staff who give the treatment may know.; Research and evidence; See also: blinding
evidence profile (evidence profiles, evidence grade, evidence grades): This site's four separate grades for each compound: testing in people, the amount of lab and animal research, how independent that research is, and what is known about harms in people.; Research and evidence; See also: preclinical research, independent replication
exendin-4 (exendin): A peptide first found in the venom of the Gila monster, a lizard. It switches on the same receptor as the human hormone GLP-1. The medicine exenatide is a lab-made version.; Biology; See also: GLP-1, GLP-1 receptor agonist
expanded access (pre-approval access, expanded access programme, expanded-access programme): In the US, a legal route in which a doctor asks the company, under the FDA's rules, for an unapproved medicine for a seriously ill patient who cannot join a trial.; Regulation; See also: compassionate use
expression of concern (Expression of Concern): A notice by a journal that it has serious doubts about a published paper, for example about its data, while it looks into it. It is a warning, not yet a retraction.; Research and evidence; See also: retraction
external validity (generalisability, generalizability): Whether a result found in one setting, such as young healthy rats, also holds in another, such as older patients with other illnesses.; Research and evidence; See also: internal validity, animal model

F

false positive (false positives, false-positive result): A result that seems to show an effect when there is none, for example by chance in a small study.; Research and evidence; See also: p-value, statistical power
falsified medicine (falsified medicines, falsified, counterfeit, counterfeit medicine, fake medicine, fake pens): A product that pretends to be a real medicine, for example by copying its packaging or batch number. Its content, dose and sterility are unknown.; Safety
FAMHP (FAGG, AFMPS, Federal Agency for Medicines and Health Products): Belgium's medicines agency. It approves and checks medicines, collects side-effect reports and acts against illegal medicines.; Regulation; See also: medicines regulator
fasting glucose (fasting blood glucose, fasting blood sugar): The level of sugar in your blood after you have eaten nothing, and drunk nothing but water, for at least 8 hours. It is usually measured in the morning.; Biology; See also: glucose, HbA1c
fat cell (adipocyte, adipocytes, fat cells, adipose tissue, white adipose tissue): A cell that stores fat. Fat tissue is mostly made of these cells, and they also send hormone signals to the rest of the body.; Biology
fatty-acid side chain (acylation, acylated, fatty diacid, C18 fatty diacid, lipidation): A fat-like chain chemically attached to a peptide drug. It makes the drug stick loosely to albumin in the blood, so the kidneys remove it much more slowly.; Chemistry; See also: albumin binding
Fc fusion (Fc fragment, Fc fusion protein, antibody part): Joining a medicine to a piece of an antibody (the Fc part). The bigger molecule is filtered less by the kidneys and lasts longer.; How drugs work in the body; See also: PEGylation
FDA (US Food and Drug Administration, Food and Drug Administration): The US Food and Drug Administration: the government body that decides which medicines may be sold in the United States.; Regulation; See also: medicines regulator
Federal Food, Drug, and Cosmetic Act (FD&C Act, FDCA): The main US federal law on medicines, foods and cosmetics. The FDA enforces it.; Law; See also: FDA, unapproved new drug
Federal Register: The official daily journal of the US government. Proposed and final rules, and notices of FDA advisory meetings, are published there.; Law; See also: rulemaking
female sexual arousal disorder (FSAD): An older diagnosis for women whose body does not become sexually aroused, or stays aroused too briefly, which causes distress. Newer manuals merge it with low desire.; Biology; See also: hypoactive sexual desire disorder
Female Sexual Distress Scale–Desire/Arousal/Orgasm (FSDS-DAO, FSDS-DAO item 13): A questionnaire about how much distress a woman feels about her sexual desire, arousal and orgasm. Item 13 asks how often low desire bothered her, from 0 (never) to 4 (always).; Research and evidence; See also: Female Sexual Function Index, hypoactive sexual desire disorder
Female Sexual Function Index (FSFI, FSFI desire domain, desire domain): A questionnaire that women fill in about their sex life over the past four weeks. Its desire part has two questions and gives a score from 1.2 to 6.; Research and evidence; See also: Female Sexual Distress Scale–Desire/Arousal/Orgasm, hypoactive sexual desire disorder
Fertigarzneimittel (ready-made medicine, ready-made medicines): German legal term for a medicine made in advance and sold in a pack meant for the user. A ready-made medicine needs a licence before it may be sold.; Law; See also: Arzneimittelgesetz
fibroblast (fibroblasts, tendon fibroblasts, tendocytes): A common cell in connective tissue such as tendon and skin. It makes collagen, the main structural protein of these tissues.; Biology
first-in-human trial (first-in-human, first-in-human trials, first in human): The first time a new medicine is given to people, often to a few healthy volunteers (for some medicines, patients), one small step at a time, under close medical watch.; Research and evidence; See also: trial phase, MABEL
first-pass metabolism (first-pass effect, first pass metabolism): Breakdown of a swallowed medicine in the gut wall or liver before it reaches the rest of the body.; How drugs work in the body; See also: bioavailability
fistula (fistulas, fistulae): An abnormal channel between two parts of the body, for example between the bowel and the skin. It can form after disease, injury or surgery.; Biology
Flemish decree (Flemish anti-doping decree): A law passed by the Flemish Parliament, for the Dutch-speaking part of Belgium. In Flanders it has the same force as a national law.; Law
flushing (vasodilatory reaction, vasodilatory reactions, systemic vasodilatory reaction): Sudden redness and warmth of the face, neck or chest, because small blood vessels in the skin widen. It can come with a short drop in blood pressure.; Safety; See also: hypotension
focal adhesion kinase (FAK, FAK–paxillin, FAK-paxillin): A protein inside cells that senses where the cell is attached to its surroundings. It helps the cell move and survive, and it is also very active in many tumours.; Biology; See also: paxillin
folate (folate cycle, folic acid): A B vitamin (vitamin B9). Cells need it to make the building blocks of DNA.; Biology
free base (acetate salt, acetate form, salt form): The plain form of a drug molecule. A salt form, such as an acetate, is the same molecule paired with a small partner molecule. Regulators treat the two as different substances.; Chemistry
freeze-drying (freeze-dried, lyophilisation, lyophilization, lyophilised, lyophilized): A way of removing water from a frozen product so that it becomes a dry powder. It helps a peptide keep longer, but it does not kill germs.; How drugs work in the body; See also: reconstitution, sterile
full agonist (full agonists): A molecule that switches a receptor on as fully as the cell allows.; How drugs work in the body; See also: agonist, partial agonist
full blood count (complete blood count, blood count, FBC, CBC): A common blood test that counts red blood cells, white blood cells and platelets. It can help find an infection, anaemia or a blood disorder.; How drugs work in the body; See also: anaemia
functional antagonism (functional antagonist, functional GIPR antagonism): When a drug that switches a receptor on is given for a long time, the cell may stop responding. The end result can then look like blocking the receptor, even though the drug is an activator.; How drugs work in the body; See also: desensitisation
functional MRI (fMRI, functional magnetic resonance imaging): A brain scan that shows which brain areas become more or less active during a task, by tracking changes in blood flow.; Research and evidence

G

G protein (G proteins): A switch protein just inside the cell wall. A switched-on receptor activates it, and it passes the signal to an enzyme.; Biology; See also: G-protein-coupled receptor, Gs protein
G-protein-coupled receptor (G-protein-coupled receptors, G protein-coupled receptor, G protein-coupled receptors, GPCR, GPCRs): A large family of receptors that sit in the cell's outer wall and pass a signal inside through a G protein. Many peptide hormones act on them.; Biology; See also: receptor, G protein, second messenger
gallbladder (gall bladder): A small pouch under the liver. It stores bile, a juice that helps the body digest fat.; Biology; See also: gallstones
gallstones (gallstone, cholelithiasis, gallbladder disease, cholecystitis): Hard lumps that form in the gallbladder. They are more common during fast weight loss and can block the bile duct or inflame the gallbladder (cholecystitis).; Safety
gastric emptying (stomach emptying, delayed gastric emptying): How fast food leaves the stomach and moves into the gut. Slower emptying means food, and some tablets, stay in the stomach longer.; Biology
gastroparesis (severe gastroparesis): A condition in which the stomach empties very slowly, without a blockage. It causes nausea, vomiting and feeling full quickly.; Biology; See also: gastric emptying
Geneesmiddelenwet (Dutch Medicines Act, Medicines Act (Netherlands), Gnw): The Dutch Medicines Act. It says what a medicine is, who may make, sell and advertise one, and what happens if someone breaks the rules.; Law; See also: marketing authorisation, IGJ
genotoxicity (genotoxic, mutagenic, Ames test): Damage to the genetic material (DNA) of cells, which can start a cancer. Genotoxicity tests check whether a substance causes this kind of damage.; Safety; See also: carcinogenicity study
GGD (GGDs, Municipal Health Service): The Dutch regional public health service. Among other things, it helps after a needle-stick injury and with sexual health, including emergency HIV treatment.; Safety; See also: post-exposure prophylaxis
ghost-writing (ghostwriting, ghost-written, ghostwritten, ghost author, ghost authors, ghost authorship): When the real writer of a paper, often paid by a company, is not named as an author.; Research and evidence; See also: guest authorship, conflict of interest
ghrelin (lenomorelin): A hormone made mainly in the stomach. It makes you feel hungry and makes the pituitary gland release growth hormone.; Biology; See also: ghrelin receptor, growth hormone
ghrelin receptor (ghrelin receptors, GHS-R1a, GHSR1a, GHS-R, growth hormone secretagogue receptor, GH secretagogue receptor): The receptor that ghrelin switches on. It sits on cells in the pituitary gland, the brain, the stomach and other organs. Ipamorelin switches on the same receptor.; Biology; See also: ghrelin, receptor, growth hormone secretagogue
gingiva: The medical word for the gums: the pink tissue around the teeth.; Biology
GIP (glucose-dependent insulinotropic polypeptide, gastric inhibitory polypeptide): A hormone made in the upper gut after a meal. Like GLP-1, it tells the pancreas to release more insulin when blood sugar is high.; Biology; See also: GIP receptor, incretin, GLP-1
GIP receptor (GIPR, GIP receptors, GIP-receptor): The receptor that the hormone GIP switches on. It is found on cells in the pancreas, in fat tissue and in parts of the brain.; Biology; See also: GIP
glomerulus (glomerular filtration, kidney filter, glomeruli): The tiny filter in the kidney that strains waste out of the blood. It lets small molecules, including most peptides, through and holds back large proteins such as albumin.; Biology; See also: clearance, albumin binding
GLP-1 (glucagon-like peptide-1, glucagon-like peptide 1, GLP-1 (7-37)): A short hormone made in the gut after a meal. It tells the pancreas to release insulin when blood sugar is high, and it helps you feel full.; Biology; See also: incretin, GLP-1 receptor agonist
GLP-1 receptor (GLP-1R, GLP-1 receptors): The receptor that the gut hormone GLP-1 switches on. It is found in the pancreas, the brain, the gut and the heart.; Biology; See also: GLP-1, GLP-1 receptor agonist
GLP-1 receptor agonist (GLP-1 receptor agonists, GLP-1 RA, GLP-1 RAs, GLP-1 agonist, GLP-1 agonists): A medicine that switches on the same receptor as the body's own GLP-1, but lasts much longer. Semaglutide, liraglutide and dulaglutide are examples.; How drugs work in the body; See also: GLP-1
glucagon: A hormone from the pancreas that tells the liver to release sugar into the blood. It works in the opposite direction to insulin.; Biology; See also: GLP-1
glucagon receptor (GCGR, glucagon receptors): The receptor that the hormone glucagon switches on. It is found mainly in the liver, where it tells cells to release sugar and use fat and amino acids.; Biology; See also: glucagon
glucose (blood glucose): The main sugar in the blood. Cells use it for energy, and insulin helps keep its level in a healthy range.; Biology; See also: insulin, hypoglycaemia, hyperglycaemia
GnRH (gonadotropin-releasing hormone): A peptide hormone from the brain, released in pulses, that tells the pituitary to release LH and FSH, which keep the sex hormones going.; Biology; See also: LH and FSH, pituitary gland
good manufacturing practice (GMP): The quality rules for making medicines. They cover clean rooms, trained staff, tested ingredients, checks on every batch and records that inspectors can see.; Regulation; See also: sterile, endotoxin
GRADE (GRADE approach, GRADE system): An international method for rating how much confidence a body of evidence deserves for one specific question, used by many guideline groups. Ratings run from high to very low.; Research and evidence; See also: systematic review
granulation tissue: The new, soft tissue that fills a wound while it heals. It is full of small new blood vessels and the cells that make collagen.; Biology; See also: angiogenesis, fibroblast
GRAS (generally recognised as safe, generally recognized as safe, GRAS notice): A US food term: 'generally recognised as safe'. A company may tell the FDA about its GRAS view; an FDA 'no questions' letter is not a medicine approval.; Law; See also: dietary supplement
growth factor (growth factors): A protein that cells release to tell other cells to grow, divide or move. Some growth factors are used as medicines, for example to help wounds heal.; Biology; See also: VEGF
growth hormone (GH): A hormone from the pituitary gland that drives growth and affects metabolism, partly by raising IGF-1. It is released in pulses.; Biology; See also: IGF-1, growth hormone releasing hormone, somatostatin
growth hormone deficiency (GHD, GH deficiency): A condition in which the pituitary gland makes too little growth hormone. In children it slows growth. It is diagnosed with special blood tests and treated with approved growth hormone.; Biology; See also: growth hormone, pituitary gland
growth hormone receptor (growth-hormone receptor, GH receptor): The receptor on a cell that growth hormone binds to. A cell with more of these receptors can respond more strongly to the same amount of hormone.; Biology
growth hormone releasing hormone (GHRH, growth-hormone-releasing hormone, growth hormone releasing hormones, growth hormone releasing factors): A hormone from the brain that tells the pituitary gland to release growth hormone. Lab-made versions such as tesamorelin and CJC-1295 copy it.; Biology; See also: growth hormone secretagogue, growth hormone releasing peptide
growth hormone releasing peptide (growth hormone releasing peptides, GHRP, GHRPs, growth-hormone-releasing peptides): A small lab-made peptide that makes the body release growth hormone. Hexarelin is one.; Biology; See also: growth hormone secretagogue, growth hormone releasing hormone
growth hormone secretagogue (growth hormone secretagogues, GHS, GH secretagogue, GH secretagogues): A substance that makes the body release more growth hormone, for example by acting like the hunger hormone ghrelin. Ipamorelin is one.; Biology; See also: growth hormone releasing hormone, growth hormone releasing peptide
Gs protein: A switch protein just inside the cell. When a receptor is activated, the Gs protein turns on an enzyme that makes the messenger cAMP.; Biology; See also: cAMP
guest authorship (honorary authorship, guest author, guest authors, honorary author, honorary authors): When someone is named as an author who did little or none of the work, often to lend the paper a respected name.; Research and evidence; See also: ghost-writing
GVS (geneesmiddelenvergoedingssysteem, Bijlage 2, medicines reimbursement system): The Dutch system that decides which prescription medicines the basic health insurance pays for. Medicines on its 'Bijlage 2' list are only paid for under set conditions.; Regulation

H

half-life (half-lives, elimination half-life): The time it takes for the amount of a drug in the blood to fall by half.; How drugs work in the body
harm reduction (harm-reduction): Helping people who use a substance anyway to lower the damage it can do, without judging them. Examples are clean needles and clear information about warning signs.; Safety
hazard ratio (hazard ratios, HR): A number that compares how often an event happens over time in two groups. A hazard ratio of 0.80 means the event happened about 20% less often in the first group.; Research and evidence
HbA1c (glycated haemoglobin, glycated hemoglobin, A1c): A blood test that shows your average blood sugar over the last two to three months. Diabetes trials use it to measure how well a treatment works.; Research and evidence
Heilmittelwerbegesetz (HWG): The German law on advertising for medicines. It bans adverts for medicines that need a licence but do not have one.; Law; See also: Arzneimittelgesetz
hepatitis B and C (hepatitis B, hepatitis C, HBV, HCV): Virus infections of the liver that can pass through blood. Both can become long-lasting and damage the liver; there is a vaccine against hepatitis B.; Safety; See also: blood-borne virus
heptapeptide (heptapeptides, seven-amino-acid peptide): A peptide made of exactly seven amino acids. TB-500 is a heptapeptide.; Chemistry; See also: thymosin beta-4
HFpEF (heart failure with preserved ejection fraction): A type of heart failure in which the heart still pumps with normal force but is too stiff to fill properly. It causes breathlessness, tiredness and swollen ankles.; Biology; See also: KCCQ
hierarchy of evidence (evidence pyramid, evidence hierarchy): A ranking of study types by how well they can show cause and effect: cell and animal studies at the bottom, randomised trials and reviews of trials near the top.; Research and evidence; See also: randomised controlled trial, systematic review
hippocampus: A part of the brain that is important for memory and learning.; Biology
histamine: A chemical that some immune cells, such as mast cells, release. It causes itching, redness and swelling, for example in an allergic reaction.; Biology; See also: mast cell
HIV (human immunodeficiency virus): A virus that weakens the immune system. HIV medicines keep it under control, so people with HIV can live long lives.; Biology; See also: antiretroviral therapy, lipodystrophy
hormone (hormones): A messenger substance that a gland releases into the blood. It travels to other organs and changes how they work. Insulin and growth hormone are examples.; Biology; See also: insulin, growth hormone
HPLC (high-performance liquid chromatography, liquid chromatography, chromatogram): A lab test that pushes a dissolved sample through a narrow column, so that different molecules come out at different times. It shows how pure a sample looks, but not by itself what the main substance is.; Chemistry; See also: mass spectrometry, certificate of analysis, impurity
huisarts (GP, general practitioner): Your family doctor in the Netherlands. You go to the huisarts first for most health problems, and they refer you to a hospital if needed.; Safety; See also: huisartsenpost
huisartsenpost (huisartsen-spoedpost, out-of-hours GP service): The Dutch out-of-hours GP service for urgent problems in the evening, at night and at weekends. Call them before you go to a hospital emergency department, unless a life is in danger.; Safety; See also: huisarts
human chorionic gonadotrophin (HCG, chorionic gonadotrophin, human chorionic gonadotropin, chorionic gonadotropin): A hormone that the placenta makes in pregnancy. As a medicine it is used in fertility treatment; in men it makes the body produce more testosterone.; Biology; See also: hormone
Human Medicines Regulations 2012 (Human Medicines Regulations): The main UK law on medicines. It says what a medicinal product is, who may sell or supply one, and which acts are crimes.; Law; See also: MHRA, unlicensed medicine
hydrocephaly (hydrocephalus, fluid on the brain): A build-up of fluid inside the spaces of the brain. In unborn animals or babies it can harm how the brain develops.; Biology
hydrogen bond (hydrogen bonds): A weak attraction between a hydrogen atom and a nearby oxygen or nitrogen atom. Many of them together hold a peptide chain in a twist or fold.; Chemistry; See also: secondary structure
hydrolysis (hydrolysed, hydrolyse, hydrolyzed): Breaking a chemical bond by adding water. Digestion breaks protein and peptides this way.; Chemistry; See also: peptide bond, protease
hydrophilic (water-loving): Attracted to water. Water-loving molecules dissolve well in blood but pass poorly through the oily walls of cells.; Chemistry; See also: cell membrane
hyperaesthesia (hyperesthesia): Skin that is more sensitive than normal to touch, heat or cold.; Safety; See also: dysaesthesia
hyperglycaemia (hyperglycemia, high blood sugar, high blood glucose): Blood sugar that is higher than normal. Signs include strong thirst, passing a lot of urine and tiredness.; Biology; See also: hypoglycaemia, HbA1c, insulin sensitivity
hyperpigmentation (focal hyperpigmentation, pigmentation changes, pigmentary changes): Patches of skin or gums that turn darker than the area around them, because pigment cells make more pigment there.; Safety; See also: melanocyte, melanocortin receptor
hyperplasia (somatotroph hyperplasia, pituitary hyperplasia): Growth of a tissue because its cells multiply. It is not cancer, but it can make an organ larger than normal.; Biology; See also: somatotroph, pituitary gland
hypersensitivity reaction (hypersensitivity reactions, hypersensitivity): An allergic-type reaction of the immune system to a medicine. It ranges from a rash or hives to, rarely, swelling of the throat and trouble breathing.; Safety; See also: anaphylaxis, anti-drug antibodies
hypertension (high blood pressure, uncontrolled hypertension): Blood pressure that is too high most of the time. It usually causes no symptoms, but over years it raises the risk of heart attack and stroke.; Safety; See also: systolic blood pressure, cardiovascular disease
hypoactive sexual desire disorder (HSDD, hypoactive sexual desire disorders, low sexual desire disorder): A diagnosis for low or absent sexual desire that causes marked distress or problems in a relationship. It only applies when another illness, a medicine or problems in the relationship do not explain it.; Biology; See also: Female Sexual Function Index, Female Sexual Distress Scale–Desire/Arousal/Orgasm
hypoglycaemia (hypoglycemia, low blood sugar, low blood glucose): Blood sugar that is too low. It can cause shaking, sweating, confusion and drowsiness, and if severe it can lead to loss of consciousness.; Safety; See also: sulfonylurea
hypokalaemia (hypokalemia, low potassium): Too little potassium in the blood. It can cause muscle weakness, cramps and an irregular heartbeat.; Biology
hypotension (low blood pressure): Blood pressure that is lower than normal. It can cause dizziness or fainting, especially when standing up.; Safety
hypothalamus: A small area at the base of the brain that controls many hormones, mostly by giving orders to the pituitary gland.; Biology; See also: pituitary gland, negative feedback

I

ibutamoren (MK-677, MK-0677, ibutamoren mesylate): A swallowed, non-peptide drug that switches on the ghrelin receptor. It was tested in trials but is not an approved medicine.; How drugs work in the body; See also: ghrelin receptor, growth hormone secretagogue
IGF-1 (insulin-like growth factor 1, insulin-like growth factor-1, IGF-I): A growth factor in the blood that carries out many effects of growth hormone. Because it is steadier than growth hormone itself, doctors measure it to see how active growth hormone is.; Biology; See also: growth factor
IGJ (Health and Youth Care Inspectorate, Inspectie Gezondheidszorg en Jeugd, health inspectorate): The Dutch Health and Youth Care Inspectorate. It checks that care and medicines follow the law, and can act against people who sell medicines illegally.; Regulation; See also: named-patient route
ileus: A condition in which the bowel stops moving food and fluid along, so they build up. It causes a swollen belly, pain and vomiting.; Safety
immune system (immune response, immune responses, immune reaction, immune reactions, immune cells): The body's defence against germs and other things it sees as foreign. It includes white blood cells and antibodies.; Biology; See also: antibody, T cell, weakened immune system
immunogenicity (immunogenic): The ability of a substance to make the immune system react against it. This can cause allergic reactions or make the body produce antibodies against the substance.; How drugs work in the body; See also: peptide aggregation
immunomodulator (immunomodulators, immunomodulatory): A medicine that changes how the immune system works, turning parts of it up or down.; How drugs work in the body
impact factor (impact metric, impact metrics, journal impact factor): A number that measures how often a journal's papers are cited on average. It says nothing about whether a single paper is right, and fake versions exist.; Research and evidence; See also: predatory journal
impurity (impurities): Anything in a product that should not be there, such as faulty copies of the peptide, leftover chemicals from making it, or metals.; Chemistry; See also: deletion sequence, HPLC
in vitro (in-vitro): An experiment done outside a living body, for example in cells grown in a dish. Latin for "in glass".; Research and evidence; See also: in vivo
in vivo (in-vivo): An experiment done in a living body, such as a mouse or a person. Latin for "in the living".; Research and evidence; See also: in vitro
inbred strain (inbred strains, inbred animals): Laboratory animals bred brother to sister for many generations, so they are almost genetically identical. That makes results tidy, and less like a varied human population.; Biology; See also: animal model
incretin (incretins, incretin hormone, incretin effect): A gut hormone that boosts insulin release after you eat. GLP-1 and GIP are the two main incretins in people.; Biology; See also: GLP-1
independent replication (replication, replicated, replicate, independently replicated): Repeating an experiment in another laboratory, by people who were not involved in the first study, to see whether the result holds.; Research and evidence; See also: publication bias
infarct size (infarcted area, infarcted areas): How much heart muscle has died after a heart attack. Doctors measure it with heart scans.; Biology
inflammation (inflamed, inflammatory): The body's response to injury or infection. The area becomes red, warm, swollen and painful while the body fights germs or repairs damage.; Biology; See also: immune system
inflammatory bowel disease (IBD, Crohn's disease, Crohn disease): A group of long-term diseases, mainly ulcerative colitis and Crohn's disease, in which the gut becomes inflamed. They need medical treatment.; Biology; See also: DSS colitis
informed consent (consent): Agreeing to a treatment after your doctor has explained what it is for, its risks, and the other options. Without your consent, nothing may be done to you.; Law; See also: WGBO
injection-site reaction (injection-site reactions, injection site reaction, injection site reactions): Redness, itching, pain or a small bruise where the needle went in. A normal one stays small and fades; one that grows may be an infection.; Safety; See also: cellulitis, abscess
inner mitochondrial membrane (inner membrane of mitochondria, inner mitochondrial membranes): The folded inner wall of a mitochondrion. This is where most of the cell's energy is made.; Biology; See also: mitochondria, cardiolipin
inotropic effect (positive inotropic effect, inotropic effects, force of contraction): A change in how strongly heart muscle squeezes. A positive inotropic effect makes it squeeze harder.; How drugs work in the body
INR (international normalised ratio, international normalized ratio): A blood test that shows how long blood takes to clot. People who take warfarin or similar medicines have it checked regularly.; How drugs work in the body; See also: narrow therapeutic index
insomnia: Trouble falling asleep or staying asleep, so that you feel tired during the day.; Biology
insulin: A hormone made by the pancreas. It helps sugar move from the blood into cells, so the blood sugar level falls. People with diabetes may need it as a medicine.; Biology; See also: pancreas, glucose, hypoglycaemia
insulin glargine (glargine, long-acting insulin): A long-acting insulin, usually injected once a day, that keeps a steady background level of insulin in the blood.; How drugs work in the body; See also: hypoglycaemia
insulin sensitivity (insulin resistance, insulin sensitiser, insulin sensitizer, insulin sensitisation, insulin sensitization): How well the body's tissues respond to insulin. With low insulin sensitivity (insulin resistance), more insulin is needed to move the same amount of sugar out of the blood.; Biology; See also: clamp study
integrin-linked kinase (ILK): A protein inside cells that passes on signals from the points where the cell holds on to its surroundings. It helps cells survive and move, and some cancer cells make more of it.; Biology; See also: Akt
intended use (intended uses, objective intent): In US law, what a seller really means a product to be used for. The FDA judges it from all the seller's words and actions, not only from the label.; Law; See also: research chemical, FDA
internal validity: Whether a study's own result is trustworthy: whether the difference it found was caused by the treatment and not by bias or chance.; Research and evidence; See also: external validity, risk of bias
International Convention against Doping in Sport (UNESCO convention): A 2005 treaty by which governments agree to support the fight against doping. Its annex is the WADA Prohibited List.; Law; See also: Prohibited List
international non-proprietary name (INN): The official generic name of a medicine, chosen through the World Health Organization, such as retatrutide or semaglutide.; Regulation
interstate commerce (trade between states): In US law, trade that crosses the border between two or more states. The federal ban on selling unapproved new drugs applies to it.; Law; See also: unapproved new drug
interstitial cystitis (bladder pain syndrome): A long-term bladder condition that causes pain and a frequent, urgent need to pass urine, without an infection.; Biology
intranasal (nasal spray, nasal sprays, nasal drops): Given into the nose, as a spray or drops, to be absorbed through the lining of the nose.; How drugs work in the body; See also: sublingual
intraperitoneal (intraperitoneally): Injected into the belly cavity, the space around the gut. It is a common route in rat and mouse studies but is not how medicines are normally given to people.; How drugs work in the body
intravenous (intravenously, into a vein): Given straight into a vein. The whole dose reaches the blood at once.; How drugs work in the body; See also: bioavailability
intrinsic efficacy: How strongly a molecule switches a receptor on once it is bound. Agonists have it; antagonists do not.; How drugs work in the body; See also: affinity, partial agonist, antagonist
Inverkehrbringen: German legal term for putting a product on the market. It covers keeping stock to sell, offering it and handing it to others, not only the sale itself.; Law; See also: Arzneimittelgesetz
inverse agonist (inverse agonists, inverse agonism): A molecule that turns down a receptor that is active on its own, the opposite of an agonist.; How drugs work in the body; See also: antagonist, agonist
investigational medicine (investigational medicines, investigational drug, investigational drugs, investigational product): A medicine that is still being tested in clinical trials and has no marketing authorisation. In the EU it may be supplied only through narrow exceptions, mainly approved trials and formal access programmes.; Regulation; See also: expanded access, trial phase
Investigator's Brochure (IB, IMPD, investigational medicinal product dossier): Files a company writes about an experimental medicine for a trial. The Investigator's Brochure is for the trial doctors. The IMPD is for the regulator. Together they describe how it is made and what animal and human studies found.; Regulation; See also: investigational medicine, clinical trial
ischaemia (ischaemic, ischemia, ischemic): A lack of blood flow to part of the body, so the tissue gets too little oxygen. When blood flow returns, the tissue can be damaged further.; Biology
ISO/IEC 17025 (ISO 17025, accredited laboratory, accredited lab): An international standard for testing laboratories. A lab that is accredited to it has been checked by an outside body on how it works and tests.; Regulation; See also: certificate of analysis

J

jaundice (yellowing of the skin): Yellow skin or yellow whites of the eyes. It can be a sign of a problem with the liver, the gallbladder or the pancreas.; Safety

K

KCCQ (Kansas City Cardiomyopathy Questionnaire, KCCQ-CSS): A questionnaire that people with heart failure fill in about their symptoms and daily limits. Scores run from 0 to 100; higher means fewer problems.; Research and evidence; See also: HFpEF
Kefauver-Harris Amendments (Kefauver-Harris, Drug Amendments of 1962, 1962 Drug Amendments): A US law of 10 October 1962. Since then, a company must show with well-controlled studies that a new medicine works, not only that it is safe, before it may be sold.; Law; See also: substantial evidence, adequate and well-controlled study, thalidomide
ketones (ketone, ketone bodies, beta-hydroxybutyrate, β-hydroxybutyrate, ketonaemia): Acids that the liver makes from fat when the body has too little sugar or too little insulin. Small amounts are normal; very high amounts make the blood acidic.; Biology; See also: diabetic ketoacidosis
key opinion leader (key opinion leaders, KOL, KOLs): An expert whom companies pay to speak, advise or teach about a product or a field, because other people trust them.; Research and evidence; See also: conflict of interest
kinase (kinases, PKA, protein kinase A): An enzyme that switches other proteins on or off by attaching a phosphate group to them. PKA is a kinase that cAMP switches on.; Biology; See also: cAMP, second messenger
klein chemisch afval (kca, small chemical waste): Dutch name for small amounts of household chemical waste, such as batteries, paint and medicines. Each municipality collects it, for example at a recycling centre (milieustraat) or with a collection van (chemokar).; Safety; See also: sharps container
KNMG (Royal Dutch Medical Association): The Royal Dutch Medical Association, the professional body for doctors in the Netherlands. It publishes guidance on how doctors should act.; Law; See also: medical confidentiality
knockout mouse (knockout mice): A mouse bred so that one gene is completely switched off. Researchers use it to see what the body needs that gene for.; Research and evidence

L

L-NAME (N(G)-nitro-L-arginine methyl ester): A laboratory chemical that blocks the enzymes that make nitric oxide. Researchers use it to test whether an effect depends on nitric oxide: if L-NAME stops the effect, nitric oxide is probably involved.; How drugs work in the body; See also: nitric oxide
lactam bridge (lactam ring, lactam bond): A chemical link that joins two side chains of the same peptide, closing it into a ring.; Chemistry; See also: cyclic peptide
Landelijk Meldpunt Zorg (national reporting point): The Dutch national reporting point of the health inspectorate (IGJ). You can report a doubtful website or seller of medicines there.; Regulation; See also: IGJ
Lareb (Bijwerkingencentrum Lareb, Netherlands Pharmacovigilance Centre): The Dutch centre that collects reports of side effects. Anyone can report a side effect to Lareb, also for a product bought online.; Safety; See also: pharmacovigilance
lean mass (lean body mass, fat-free mass): Everything in the body that is not fat: muscle, but also organs, bone and water. A fall in lean mass is not the same as an equal fall in muscle.; Biology
legal supply chain: The official route a medicine takes from its maker to a pharmacy or hospital. Every firm on the way needs a licence, and regulators check them.; Regulation; See also: falsified medicine
LH and FSH (LH, FSH, luteinising hormone, follicle-stimulating hormone): Two hormones from the pituitary gland that make the testes and ovaries produce sex hormones and sperm or eggs.; Biology; See also: GnRH
lipodystrophy (HIV-associated lipodystrophy, lipodystrophies): A change in where the body stores fat. In some people on HIV treatment, fat is lost in some places and builds up in the belly.; Biology; See also: visceral fat, HIV
lipohypertrophy (lipohypertrophies): Lumps of thickened fat under the skin where someone has injected many times in the same place. A medicine injected into them is absorbed unevenly.; Safety; See also: subcutaneous
lipolysis (fat breakdown, breakdown of stored fat): The breakdown of stored fat into fatty acids that the body can use for energy.; Biology; See also: visceral fat, growth hormone
liver fibrosis (liver scarring, fibrosis of the liver): Scar tissue that builds up in the liver after long-lasting damage, for example from too much fat. Severe scarring is called cirrhosis.; Biology; See also: MASLD, biopsy
liver tests (liver function tests, liver function test, LFTs): Blood tests that measure enzymes and other substances made or handled by the liver. An abnormal result can mean the liver is under stress, but more tests are needed to find the cause.; How drugs work in the body; See also: ALT, jaundice
LL-37: A small protein that the body makes in the skin, the gut and white blood cells. It helps to kill germs.; Biology; See also: peptide
lymph (lymphatics, lymphatic system, lymph vessels): Clear fluid that drains from tissues through its own vessels back into the blood. Large molecules injected under the skin travel partly this way.; Biology; See also: subcutaneous
lymphangitis (red streaks): An infection of the lymph vessels, the thin channels that drain fluid from tissues. It shows as red lines running from an infected spot towards the armpit or groin.; Safety; See also: cellulitis, sepsis

M

M2.2 (IV infusion limit) (M2.2, IV infusion rule): The anti-doping rule that bans drips or injections of more than 100 mL in 12 hours, whatever they contain, unless given in hospital care or with an exemption.; Sport; See also: Prohibited List, Therapeutic Use Exemption
MABEL (minimal anticipated biological effect level): The lowest amount expected to have any effect at all in people, estimated from laboratory and animal data, ideally including human cells. European guidance asks for it when the first dose for people is chosen.; Regulation; See also: first-in-human trial, NOAEL
MACE (major adverse cardiovascular events, major adverse cardiovascular event): A combined trial outcome that usually counts death from heart or blood-vessel disease, non-fatal heart attack and non-fatal stroke.; Research and evidence
macimorelin (Ghryvelin, Macrilen): A medicine taken once by mouth as a test for growth hormone deficiency in adults. It switches on receptors in the pituitary gland. It is approved in the EU and the US.; How drugs work in the body; See also: growth hormone deficiency, ghrelin receptor
magistral preparation (magistrale bereiding, magistral formula, pharmacy preparation, pharmacy preparations, apotheekbereiding): A medicine that a pharmacy makes itself for one named patient, on a doctor's prescription. It needs no marketing authorisation, but it must still meet quality rules.; Regulation; See also: pharmacopoeia, compounding
maleimide (maleimide group, maleimido group, maleimidopropionic acid): A small, reactive ring of atoms. It forms a lasting bond with a sulfur group on proteins such as albumin.; Chemistry; See also: covalent bond, drug affinity complex
marketing authorisation (marketing authorisations, marketing authorization, handelsvergunning): The licence a medicine needs before it may be sold. A regulator gives it only after checking the medicine's quality, its effects and its risks.; Regulation; See also: medicines regulator, prescription-only medicine
marketing authorisation holder (marketing authorisation holders, licence holder): The company that holds the licence for a medicine. It is responsible for the medicine's quality and must collect and report its side effects.; Regulation; See also: marketing authorisation, pharmacovigilance
MASH (metabolic dysfunction-associated steatohepatitis, NASH, non-alcoholic steatohepatitis): A liver disease in which fat builds up in the liver and causes inflammation and scarring. It is linked to obesity and type 2 diabetes.; Biology
MASLD (metabolic dysfunction-associated steatotic liver disease, fatty liver disease, fatty liver): Too much fat stored in the liver, linked to overweight, diabetes and high blood fats. Over years it can lead to liver inflammation and scarring.; Biology; See also: MASH
mass spectrometry (LC-HRMS, LC-MS, mass spectrometer): A laboratory method that identifies molecules by weighing them very precisely. Anti-doping laboratories use it to find drugs in blood and urine.; Chemistry
mast cell (mast cells): An immune cell found in the skin and other tissues. When it is triggered it releases histamine and other substances that cause itching, redness and swelling.; Biology
maximum tolerated dose (MTD, maximum tolerated doses): In a trial, the highest dose each person could take without side effects that made them stop. It differs from person to person.; Research and evidence
MC3 receptor (MC3R, melanocortin-3 receptor, melanocortin 3 receptor, MC3 receptors): One of the five melanocortin receptors. It is found mainly in the brain, where it helps control appetite and energy use.; Biology; See also: melanocortin receptor, MC4 receptor
MC4 receptor (MC4R, melanocortin-4 receptor, melanocortin 4 receptor, MC4 receptors): A receptor for melanocortin hormones, found mainly on nerve cells in the brain. It helps control appetite and is linked to sexual function and blood pressure.; Biology; See also: melanocortin receptor, alpha-MSH, hypothalamus
mechano growth factor (MGF, PEG-MGF, pegylated mechano growth factor): A form of IGF-1 that muscle makes after strain or injury. PEG-MGF is a lab-made version with PEG chains attached, so that it stays longer in the body.; Biology; See also: IGF-1, PEGylation
medial preoptic area (mPOA): A small region at the front of the hypothalamus in the brain. In animals it is important for sexual behaviour.; Biology; See also: hypothalamus, dopamine
median (medians): The middle value when all results are put in order from low to high. Half of the results are above it and half below, so a few extreme results do not pull it up or down.; Research and evidence
medical confidentiality (beroepsgeheim, medisch beroepsgeheim, duty of confidentiality): A doctor's duty to keep private what they learn about you as a patient. In the Netherlands there are only a few special situations in which a doctor may or must share it.; Law; See also: huisarts
medical file (medical files, medical record, medical records, patient file): The record your doctor keeps about your health and treatment. In the Netherlands it is private, and you can ask to see it and get a copy.; Law; See also: WGBO, medical confidentiality
medical need programme (medical need programmes, MNP, unmet medical need programme): In Belgium, a programme that lets doctors use an approved medicine for a serious illness it is not yet approved for, while that use is being studied or assessed.; Regulation; See also: compassionate use, off-label
medicine by function (medicinal product by function, medicines by function, by function): A product counts as a medicine if it can really change how the body works through a drug-like effect. Courts look at what the substance does, case by case.; Law; See also: medicine by presentation
medicine by presentation (medicinal product by presentation, medicines by presentation, by presentation): A product counts as a medicine if it is presented as treating or preventing disease. Words, pictures, claims and the shape of the product all count, not only the label.; Law; See also: medicine by function, research chemical
medicines regulator (regulator, regulators, medicines regulators): A government body that decides whether a medicine may be sold, and keeps watching its safety afterwards. Examples are the EMA in the EU, the CBG in the Netherlands and the FDA in the US.; Regulation; See also: marketing authorisation, EMA, CBG, FDA
MedlinePlus: A US health website for patients, run by the National Library of Medicine.; Safety; See also: PubMed
medullary thyroid carcinoma (MTC, medullary thyroid cancer): A rare type of thyroid cancer that starts in the C-cells of the thyroid gland, the cells that make the hormone calcitonin.; Safety; See also: thyroid C-cells, MEN 2
MedWatch (FDA MedWatch): The US system for reporting side effects and problems with medicines to the FDA. Patients and health workers can both use it.; Regulation
melanin (eumelanin, melanins): The dark pigment that colours skin, hair and eyes. Pigment cells make it and pass it to the skin cells around them; it absorbs part of the sun's ultraviolet light.; Biology; See also: melanocyte, tyrosinase
melanocortin (melanocortins, melanocortin peptide, melanocortin peptides): A family of hormones that affect skin colour, hunger and sex drive through melanocortin receptors. Melanotan II and PT-141 are lab-made versions.; Biology; See also: melanocortin receptor, alpha-MSH, proopiomelanocortin
melanocortin receptor (melanocortin receptors, MC1R, melanocortin-1 receptor, melanocortin receptor 1, MC receptors): A set of receptors on cells that alpha-MSH switches on. One of them, in skin cells, controls pigment. KPV does not appear to bind these receptors.; Biology; See also: alpha-MSH
melanocyte (melanocytes, pigment cells, pigment cell): A skin cell that makes the dark pigment melanin.; Biology; See also: melanocortin receptor
melanoma (melanomas): A type of skin cancer that starts in pigment cells, often in a mole that changes size, shape or colour.; Biology
melanoma in situ (melanomas in situ): The earliest stage of melanoma: the cancer cells are still only in the top layer of the skin. Removing it by surgery usually cures it.; Biology; See also: melanoma, dysplastic naevus
melatonin: A hormone the pineal gland makes in the dark. It helps set the body's day-night rhythm.; Biology; See also: pineal gland
MEN 2 (MEN2, multiple endocrine neoplasia type 2, Multiple Endocrine Neoplasia syndrome type 2): An inherited condition that gives a very high risk of medullary thyroid carcinoma and some other hormone-gland tumours.; Safety; See also: medullary thyroid carcinoma
menopause (postmenopausal, menopausal): The time in a woman's life, usually between about 45 and 55, when her periods stop for good.; Biology; See also: premenopausal
meta-analysis (meta-analyses, pooled analysis): A calculation that combines the results of several studies into one overall estimate. It is only as good as the studies that go into it.; Research and evidence; See also: systematic review
metabolite (metabolites, breakdown product, breakdown products): A smaller substance the body makes when it breaks down a drug. A metabolite can be active, inactive or harmful.; How drugs work in the body
metastasis (metastases, metastatic, lung metastases): When cancer cells leave the first tumour and grow in another part of the body.; Biology; See also: epithelial-mesenchymal transition
METC (medical ethics review committee, medical research ethics committee, ethics committee, medisch-ethische toetsingscommissie): A committee of doctors, lawyers and others that checks a study plan before it may start. It asks whether the study is useful and not too risky for the people in it.; Regulation; See also: CCMO, informed consent
metformin: The most common first tablet for type 2 diabetes. It lowers the amount of sugar the liver releases into the blood.; How drugs work in the body
MHRA (Medicines and Healthcare products Regulatory Agency): The UK medicines regulator. It licenses medicines, runs the Yellow Card scheme and has its own unit that investigates crimes involving medicines.; Regulation; See also: Yellow Card, Human Medicines Regulations 2012
migraine (migraines): A strong headache that keeps coming back, often on one side of the head. Many people also feel sick or find light hard to bear.; Biology
Misuse of Drugs Act (Misuse of Drugs Act 1971): The UK law on controlled drugs. It sorts them into Class A, B and C, with criminal penalties for owning or supplying them.; Law; See also: Class C drug
mitochondria (mitochondrion, mitochondrial): Tiny parts inside cells that turn food into energy the cell can use. They carry a small set of their own genes, separate from the cell's main DNA.; Biology; See also: mitochondrial-derived peptide
mitochondrial-derived peptide (mitochondrial-derived peptides, mitochondria-derived peptide): A short peptide whose recipe sits in the mitochondria's own genes rather than in the cell's main DNA. MOTS-c and humanin are examples.; Biology; See also: mitochondria
Mod GRF (1-29) (Mod GRF, mod-GRF, modified GRF (1-29), modified GRF 1-29, CJC-1295 without DAC, CJC-1295 no DAC): A lab-made peptide of 29 amino acids, based on the first part of the hormone GHRH. It is the CJC-1295 chain without the drug affinity complex, and no study in people has been published.; Chemistry; See also: drug affinity complex, growth hormone releasing hormone
mole (naevus) (mole, moles, naevus, naevi, nevus, nevi, melanocytic naevus, melanocytic naevi): A small spot on the skin made of a cluster of pigment cells. Most moles are harmless, but a new or changing mole should be checked, because melanoma can start in or look like one.; Biology; See also: melanocyte, dysplastic naevus, melanoma
monoclonal antibody (monoclonal antibodies): A lab-made antibody designed to attach to one specific target in the body. Many modern medicines are monoclonal antibodies.; Biology
MRA country (MRA countries, mutual recognition agreement): A country outside the EU that has an agreement with the EU to accept each other's checks on how medicines are made.; Regulation; See also: good manufacturing practice
multi-dose vial (multi-dose vials, multidose vial, multidose vials): A vial meant to be used several times. It usually contains a preservative, but each time a needle goes in, germs can get in too.; Safety; See also: single-dose vial, preservative
multicentre trial (multicentre trials, multicentre, multicenter trial, multicenter): A trial run at several hospitals or clinics at the same time, all following the same plan.; Research and evidence
myalgia (muscle pain, muscle pains, muscle aches): Pain or aching in the muscles.; Biology; See also: arthralgia
myeloperoxidase (MPO): An enzyme carried by neutrophils, a type of white blood cell. Measuring it in tissue is a common way to estimate how many of these inflammatory cells are present.; Biology; See also: cytokine

N

N-terminus (N-termini, amino end): The start of a peptide chain, where a free amino group sits unless it has been changed. Sequences are written from here.; Chemistry; See also: C-terminus
NAD+ (NAD, nicotinamide adenine dinucleotide, nadide, coenzyme I): A small molecule in every cell that carries energy-related chemical reactions and helps some repair enzymes. It is made from vitamin B3.; Biology; See also: coenzyme, niacin, nicotinamide riboside, nicotinamide mononucleotide
NADO (national anti-doping organisation, national anti-doping organisations, NADOs): The body that runs doping tests and anti-doping rules in a country or region. Belgium has four.; Sport; See also: WADA, Dopingautoriteit
NAION (non-arteritic anterior ischaemic optic neuropathy, non-arteritic anterior ischemic optic neuropathy): A rare eye condition in which blood flow to the front of the optic nerve drops. It usually causes sudden, painless loss of vision in one eye, which may not recover.; Safety
naltrexone: A medicine that blocks opioid receptors. Taken by mouth, it helps people stay off alcohol or opioids.; How drugs work in the body
named-patient route (artsenverklaring, doctor's declaration, named-patient use): A narrow exception that lets one patient get a medicine that has no licence in the Netherlands. The doctor must state that approved medicines cannot be used, and the inspectorate (IGJ) must agree.; Regulation; See also: IGJ, compassionate use, marketing authorisation
naphthylalanine (2-naphthylalanine, D-2Nal, 2Nal, D-2-Nal): An amino acid that the body does not use to build proteins. It is added in the lab. Ipamorelin contains its mirror-image (D) form.; Chemistry; See also: D-amino acid, Aib
narcolepsy: A long-term brain condition that makes people very sleepy during the day. They may fall asleep suddenly, at any time.; Biology
narrative review (narrative reviews, review article, review articles): A review in which the authors choose which studies to discuss, without a set search method. Useful as an overview, but open to the authors' own selection.; Research and evidence; See also: systematic review
narrow therapeutic index (narrow therapeutic range, narrow therapeutic window): A medicine for which the amount that works is close to the amount that harms, such as warfarin or digoxin. Small changes in absorption can matter.; How drugs work in the body
national marketing authorisation (national authorisation, authorised nationally, nationally authorised): A licence to sell a medicine given by one country's regulator. It applies in that country only, not in the rest of the EU.; Regulation; See also: marketing authorisation, centralised procedure
natural frequency (natural frequencies): A risk written as a count of people, such as "15 in 1,000", rather than as a percentage or a ratio. Most people find counts easier to understand.; Research and evidence; See also: absolute risk
nausea (nauseous): Feeling sick, as if you might vomit. It is a common side effect of many medicines.; Safety; See also: antiemetic
necrotising fasciitis (necrotizing fasciitis, flesh-eating disease): A rare, fast-spreading bacterial infection of the deep layers under the skin. The pain is much worse than the skin looks, and it needs emergency surgery and antibiotics.; Safety; See also: cellulitis, sepsis
needle-stick injury (needle-stick, needlestick, needle-stick injuries, prikaccident, prikaccidenten): A prick from a needle that someone has already used. It can pass on blood-borne viruses such as HIV and hepatitis B or C.; Safety; See also: post-exposure prophylaxis, blood-borne virus, sharps container
negative feedback (negative feedback loop, negative feedback loops, feedback loop, feedback loops): A control loop in which a result slows its own source, like a thermostat. Many hormone systems are controlled this way.; Biology; See also: hypothalamus, pituitary gland
network meta-analysis (network meta-analyses): A method that combines many trials to compare treatments, including treatments never tested against each other directly. Such indirect comparisons are less certain than head-to-head trials.; Research and evidence
neurasthenia: An older diagnosis for long-lasting tiredness and weakness, often with poor concentration and irritability.; Biology
neurotrophic keratopathy (neurotrophic keratitis, neurotrophic corneal defects): An eye disease in which damaged nerves stop the clear front of the eye (the cornea) from healing. Small wounds on the eye surface stay open and can scar.; Biology; See also: cornea
neutral endopeptidase (NEP): An enzyme that cuts peptides. It is one of the enzymes that break down semaglutide.; Biology; See also: protease
neutralising antibodies (neutralizing antibodies, neutralising antibody, blocking antibodies): Antibodies that stop a medicine from working, not only stick to it.; Biology; See also: anti-drug antibodies, immunogenicity
new dietary ingredient (NDI, new dietary ingredient notification): In the US, a supplement ingredient not sold before October 1994. The maker must tell the FDA why it is expected to be safe before selling it.; Law; See also: dietary supplement
NF-κB (NF-kB, NF-kappaB, nuclear factor kappa B, nuclear factor-κB): A control switch inside cells that turns on many inflammation genes. When it moves into the cell's nucleus, the cell makes more inflammatory signals.; Biology; See also: cytokine
NHG (Nederlands Huisartsen Genootschap, Dutch College of General Practitioners): The Dutch College of General Practitioners. It writes the guidelines Dutch GPs work by, and runs the patient website Thuisarts.; Law; See also: NHG-Standaard, huisarts
NHG-Standaard (NHG-Standaarden, NHG standard, NHG guideline): A treatment guideline for Dutch GPs, written by the Dutch College of General Practitioners (NHG).; Regulation
NHS (National Health Service): The National Health Service, the public health service of the United Kingdom. Its website gives advice for patients.; Regulation
niacin (vitamin B3, nicotinic acid): Vitamin B3. It comes in several forms, such as nicotinic acid and nicotinamide, found in food. The body uses them to make NAD+.; Biology; See also: NAD+
nicht geringe Menge: German for 'not a small amount'. Under the German anti-doping law, owning this amount or more of a listed substance, for doping in sport, is a crime. A regulation sets the amount for each substance.; Law; See also: Anti-Doping-Gesetz
nicotinamide mononucleotide (NMN, beta-NMN, β-NMN): A molecule one step before NAD+ in the cell. It is sold as a supplement, but in the EU it is not yet authorised as a food.; Biology; See also: NAD+, novel food
nicotinamide riboside (NR, nicotinamide riboside chloride): A form of vitamin B3 that cells can turn into NAD+. It is sold as a food supplement.; Biology; See also: NAD+, niacin, novel food
nitric oxide (NO-system, NO system): A very small gas molecule that cells use as a signal. In blood vessels it relaxes the vessel wall, so the vessel widens.; Biology; See also: eNOS
NOAEL (no-observed-adverse-effect level, no-observed-adverse-event level): The highest dose in an animal study at which no harmful effects were seen. It only applies to that species, route and study length.; How drugs work in the body
non-inferiority trial (non-inferiority, noninferiority, non-inferior, noninferior): A trial designed to show that a new treatment is not worse than an existing one by more than a set margin. It is not designed to show that the new treatment is better.; Research and evidence
nootropic (nootropics): A loose word for substances said to improve memory or thinking. It is not a medical diagnosis or a group of approved medicines.; How drugs work in the body
norleucine (Nle): A building block similar to the amino acid leucine, but with a straight side chain. Human proteins do not use it; chemists add it to make peptides more stable.; Chemistry; See also: amino acid
novel food (novel foods, Union list of novel foods): In EU law, a food or ingredient that was not commonly eaten in the EU in the past. It may only be sold after a safety check and an EU authorisation.; Law; See also: EFSA
number needed to treat (NNT, numbers needed to treat): How many people need a treatment for one of them to avoid one bad outcome over a given time. It is 100 divided by the absolute difference in percentage points.; Research and evidence; See also: absolute risk
NVIC (Nationaal Vergiftigingen Informatie Centrum, Dutch Poisons Information Centre): The Dutch poison information centre. It advises doctors, pharmacists and other professionals. If you think you are poisoned, call your GP or the huisartsenpost, and they can contact it.; Safety; See also: huisartsenpost
NVWA (Netherlands Food and Consumer Product Safety Authority, Nederlandse Voedsel- en Warenautoriteit): The Dutch food and consumer product safety authority. Together with the IGJ it watches over the Medicines Act.; Regulation; See also: IGJ

O

observational study (observational studies, observational evidence, observational research): A study that watches what happens to people who chose, or were given, a treatment in daily life. Nobody decides by chance who gets what, so other differences between the groups can explain the result.; Research and evidence; See also: confounding, cohort study, randomised controlled trial
obstructive sleep apnoea (OSA, sleep apnoea, obstructive sleep apnea, sleep apnea): A condition in which the throat keeps closing during sleep, so breathing stops or becomes very shallow many times a night. It is more common with obesity.; Biology; See also: apnoea–hypopnoea index
odds ratio (odds ratios): A number that compares the chance of something happening in two groups. An odds ratio of 1 means no difference; above 1 means it happened more often in the first group.; Research and evidence; See also: effect size
oedema (edema, fluid retention, water retention): Swelling caused by fluid building up in the body, often in the ankles, feet or legs.; Biology
off-label (off-label use, off-label prescribing, off label): Using an approved medicine for something it was not approved for. In the Netherlands a doctor may do this only if professional guidelines exist for that use. While they are still being written, the doctor must first talk it through with the pharmacist.; Regulation; See also: marketing authorisation
off-target effect (off-target effects, off-target): An effect caused by a drug acting on something other than its intended target.; How drugs work in the body; See also: selectivity
on-label: Using a medicine for the illness, the people and in the way that its approval covers. These are written on its official label.; Regulation; See also: off-label
open-label (open label, unblinded): A trial in which participants and doctors know which treatment each person gets. This can affect reported side effects and behaviour, such as eating less.; Research and evidence
opioid (opioids): A substance that acts on the opioid receptors in the brain and body, which damp down pain. Morphine and heroin are opioids, and the body makes its own, such as enkephalins.; How drugs work in the body; See also: enkephalin
Ordnungswidrigkeit: German for an administrative offence. An authority can punish it with a fine. It is not a criminal conviction.; Law; See also: administrative fine
organ bath (organ baths, lab bath): A laboratory set-up in which a small piece of tissue, such as a ring of artery, is kept alive in warm, oxygenated fluid. Researchers add a substance and measure whether the tissue tightens or relaxes.; How drugs work in the body
orphan designation (orphan drug designation, orphan status): A label a regulator gives a medicine that is still being developed for a rare disease. It brings help for the developer. It is not an approval to sell the medicine.; Regulation; See also: orphan medicine
orphan medicine (orphan medicines, orphan drug, orphan drugs): A medicine for a rare disease. Special laws in the US (since 1983) and the EU (since 2000) encourage companies to develop them.; Regulation; See also: authorisation under exceptional circumstances
osteocalcin: A protein made by bone-building cells. Its level in blood is used as a sign of how fast bone is being renewed.; Biology
osteoporosis: A condition in which bones become thin and weak, so they break more easily.; Biology
out-of-court settlement (settlement, minnelijke schikking, transactie): A sum you can pay to close a case, so that it does not go to a criminal court.; Law
outsourcing facility (outsourcing facilities, 503B, 503B outsourcing facility, 503B bulks list): A type of US compounding facility registered with the FDA under section 503B of US law. It may only compound from raw drug substance if that substance is on an FDA list of clinical need or the medicine is officially in shortage.; Regulation; See also: compounding, 503A bulks list
oxidative stress: Damage to cells from reactive forms of oxygen, such as hydrogen peroxide. Cells under oxidative stress can stop working or die.; Biology
oxytocin: A short peptide hormone. It makes the womb contract during birth and helps release breast milk. In 1953 it was the first peptide hormone made in a laboratory.; Biology; See also: peptide

P

p-value (p-values, P value, P values, statistically significant, statistical significance, not statistically significant): A number that says how surprising the data would be if the treatment had no effect at all and the study was done properly. A small p-value is called statistically significant. It does not say how big or how important an effect is.; Research and evidence; See also: effect size, confidence interval, false positive
palpitations (palpitation): Feeling your own heartbeat as pounding, racing, fluttering or skipping.; Safety; See also: arrhythmia
pancreas: An organ behind the stomach. It makes insulin and other hormones that control blood sugar, and juices that help digest food.; Biology; See also: insulin, acute pancreatitis
paraesthesia (paresthesia, paraesthesias, pins and needles): Tingling, pricking or numbness of the skin, like pins and needles, without an obvious cause.; Biology; See also: carpal tunnel syndrome
partial agonist (partial agonists, partial agonism): A molecule that switches a receptor on only part of the way, even when it fills every receptor. It can weaken the effect of a stronger agonist.; How drugs work in the body; See also: full agonist, antagonist
Paul-Ehrlich-Institut (PEI): A German federal institute for vaccines and medicines made from living material. With the BfArM, it runs the German portal for reporting side effects.; Regulation; See also: BfArM
paxillin: A support protein at the points where a cell holds on to its surroundings. It works together with focal adhesion kinase when a cell moves.; Biology; See also: focal adhesion kinase
PCAC (Pharmacy Compounding Advisory Committee): An expert committee that advises the US Food and Drug Administration (FDA) on pharmacy compounding. Its votes are advice; the FDA does not have to follow them.; Regulation; See also: 503A bulks list
PDE5 inhibitor (PDE5 inhibitors, phosphodiesterase type 5 inhibitor, phosphodiesterase-5 inhibitor): A group of medicines for erection problems, such as sildenafil (Viagra). They help blood flow into the penis during sexual arousal.; How drugs work in the body; See also: erectile dysfunction
peer review (peer-reviewed, peer reviewed): Checking of a study by independent experts before a journal publishes it. It catches some errors, but it does not prove that the results are right.; Research and evidence
PEGylation (pegylation, polyethylene glycol, PEG chains): Attaching chains of polyethylene glycol (PEG) to a medicine. It makes the molecule bigger, so the kidneys filter it less, and shields it from enzymes.; How drugs work in the body; See also: glomerulus, protease
pentadecapeptide (pentadecapeptides): A peptide made of exactly 15 amino acids. BPC-157 is a pentadecapeptide.; Chemistry
pentapeptide (pentapeptides, five-amino-acid peptide): A peptide made of five amino acids joined in a chain.; Chemistry; See also: peptide
pepsin: The main protein-cutting enzyme of the stomach. It works in strong acid and stops working when the acid is neutralised.; Biology; See also: protease, trypsin
PepT1 (PEPT1, peptide transporter 1, SLC15A1, di/tripeptide transporter): A doorway protein on the surface of gut and some immune cells that carries small peptides of two or three amino acids into the cell. It is scarce in a healthy colon but increases when the colon is inflamed.; Biology; See also: tripeptide
peptide (peptides): A short chain of amino acids, typically 2 to about 50, joined by peptide bonds. Many hormones and some medicines are peptides.; Chemistry; See also: amino acid, polypeptide, protein
peptide aggregation (aggregation, peptide aggregates): When single peptide molecules stick together into clumps. Clumps can make a product less active and more likely to trigger the immune system.; Chemistry; See also: immunogenicity
peptide bond (peptide bonds, amide bond, amide bonds): The chemical link between two amino acids in a chain. Digestive and other enzymes break it by adding water (hydrolysis).; Chemistry; See also: amino acid, hydrolysis, protease
personal importation (personal import, importing for personal use): Bringing a medicine into a country for your own use, in your luggage or by post, rather than to sell it.; Law
pharmacodynamics (pharmacodynamic, PD): What a drug does to the body, and how that effect changes with the amount in the blood.; How drugs work in the body; See also: pharmacokinetics
pharmacokinetics (pharmacokinetic, PK): What the body does to a medicine: how it is absorbed, spread, broken down and removed, and how fast.; How drugs work in the body; See also: ADME, half-life, bioavailability
pharmacophore (message sequence): The part of a molecule that is responsible for its main action. In alpha-MSH, a different part controls pigment from the part that calms inflammation.; How drugs work in the body
pharmacopoeia (European Pharmacopoeia, Ph. Eur., pharmacopoeias): An official book of quality standards for medicines and their ingredients. It says how pure a substance must be and how to test it.; Regulation; See also: good manufacturing practice
pharmacopoeia monograph (USP monograph, monograph, monographs): An official quality standard for a medicine ingredient: how to test it and what limits it must meet.; Regulation; See also: bulk drug substance
pharmacovigilance: Watching for and studying the side effects of medicines once people use them, for example through reports from patients and doctors.; Safety
pilot study (pilot studies, pilot trial, pilot trials, pilot phase 1): A small first study that tests whether a larger study can be done. It is too small to show whether a treatment works.; Research and evidence
pineal gland (pineal, epiphysis): A small gland deep in the brain that makes the hormone melatonin, mostly at night.; Biology; See also: melatonin
pituitary gland (pituitary): A pea-sized gland under the brain that releases hormones, such as growth hormone, LH and FSH, which control other glands.; Biology; See also: hypothalamus
pivotal trial (pivotal trials): A large trial that a company runs to show a regulator that its medicine works and is safe enough. The decision to approve a medicine rests mainly on these trials.; Research and evidence; See also: randomised controlled trial
placebo (placebos, dummy treatment, placebo-controlled): A dummy treatment that looks like the real one but contains no active drug. Comparing the two shows how much of an effect comes from the drug itself.; Research and evidence; See also: regression to the mean
plasma (blood plasma): The liquid part of blood, without the blood cells. It carries food substances, hormones and medicines around the body.; Biology
platelets (platelet): Tiny cells in the blood that help it clot and stop bleeding.; Biology; See also: full blood count
plenary vote (plenary, plenary date): A vote by all members of the European Parliament together. It comes after a committee has worked on the text.; Law
polypeptide (polypeptides): A longer chain of amino acids. One or more polypeptides fold together to make a protein.; Chemistry; See also: peptide, protein
post hoc analysis (post hoc analyses, post-hoc analysis, post hoc): An analysis that researchers chose after the data were collected. It can suggest ideas, but it is weaker evidence than an analysis planned in advance.; Research and evidence
post-exposure prophylaxis (PEP): Emergency treatment after a possible exposure to HIV or hepatitis B, for example after a needle-stick injury. For HIV it works best if started within hours, and it no longer works after 72 hours.; Safety; See also: needle-stick injury, blood-borne virus
post-marketing surveillance (post-marketing, postmarketing surveillance, post-marketing safety monitoring): The tracking of side effects after a medicine is on the market, when far more people use it than in the trials. It is how rare harms are found.; Safety; See also: pharmacovigilance
posterior reversible encephalopathy syndrome (PRES): Swelling in the back of the brain, often linked to swings in blood pressure. It can cause headache, fits and other brain symptoms, and in most people it gets better.; Safety; See also: hypertension
postmarketing requirement (postmarketing requirements, post-marketing requirement, post-marketing requirements): A study that a regulator orders a company to carry out after a medicine is approved, to answer safety questions that were still open.; Regulation; See also: post-marketing surveillance
postoperative ileus (post-operative ileus, POI): A short pause in the movement of the bowel after an operation. Food and gas cannot pass normally, which causes bloating, sickness and a longer hospital stay.; Biology; See also: ileus
potency (potent): How much of a drug is needed for a given effect. A potent drug works at a small amount.; How drugs work in the body; See also: affinity, intrinsic efficacy
pre-registration (preregistration, pre-registered, preregistered, trial registration, registered trial, trial registry, trial registries): Publishing a study's plan, including its main outcome, in a public register before it starts. Later changes to the plan can then be seen.; Research and evidence; See also: selective outcome reporting, primary endpoint
preclinical research (preclinical, preclinical studies, preclinical volume): Research done in cells and animals before a substance is tested in people. It can show a reason to test something, but not that it works in people.; Research and evidence; See also: in vitro, in vivo, clinical trial
precursor (precursors): A substance that the body turns into another substance. NAD+ precursors are forms of vitamin B3 that cells turn into NAD+.; Biology; See also: NAD+, niacin
predatory journal (predatory journals, predatory publisher, predatory publishers, predatory publishing): A publication that charges authors to publish but skips real peer review and editing, so almost anything gets printed.; Research and evidence; See also: peer review, impact factor
prediabetes (pre-diabetes): Blood sugar that is higher than normal but not yet high enough to count as type 2 diabetes. People with prediabetes have a higher chance of developing diabetes.; Biology; See also: HbA1c
pregnancy registry (pregnancy exposure registry): A study that collects information on women who used a medicine while pregnant, and on their babies, to find out whether the medicine causes harm.; Regulation; See also: postmarketing requirement
premenopausal (before the menopause): Before the menopause: a woman who still has periods.; Biology
preprint (preprints, preprint server, preprint servers): A research paper posted online before peer review. Anyone can read it early, but no outside expert has checked it yet.; Research and evidence; See also: peer review
prescription-only medicine (prescription-only medicines, prescription-only, UR-geneesmiddel, UR-geneesmiddelen): A medicine you can only get with a doctor's prescription, from a pharmacy. In the Netherlands, a pharmacist may not hand it over without one.; Regulation; See also: marketing authorisation
preservative (preservatives, antimicrobial preservative, bacteriostat): A substance added to a medicine to slow the growth of bacteria after the vial is opened. It does not stop viruses and does not make a contaminated vial clean.; Safety; See also: multi-dose vial, bacteriostatic water
pressure ulcer (pressure ulcers, bedsore, bedsores): Damage to the skin and the tissue under it, caused by pressure over a long time, for example from lying in bed without moving.; Biology
priapism: An erection that lasts for hours and does not go down, often painful. It is an emergency, because trapped blood can damage the penis for good.; Safety
primary endpoint (primary endpoints, primary outcome, primary outcomes): The main result a trial was designed to measure, chosen before it starts. Other results are less reliable, because with many measures some differ by chance.; Research and evidence; See also: subgroup analysis
primary mitochondrial myopathy (primary mitochondrial myopathies, PMM): A group of inherited diseases in which faulty mitochondria make the muscles weak and tired.; Biology; See also: mitochondria
primary structure: The order of the amino acids in a peptide or protein chain: its sequence.; Chemistry; See also: secondary structure, tertiary structure
PRIME scheme (PRIME priority medicines scheme, priority medicines scheme): An EU programme, started in 2016, in which the European Medicines Agency gives early advice to developers of medicines for unmet needs, to speed up their development and review.; Regulation; See also: accelerated assessment
Prohibited List (WADA Prohibited List, Prohibited Lists): WADA's yearly list of substances and methods banned in sport. A new list takes effect each 1 January.; Sport; See also: WADA, S0 (non-approved substances), S2 (peptide hormones and growth factors)
prolactin (PRL): A hormone from the pituitary gland. It starts milk production after birth. Too much can affect periods, fertility and sex drive.; Biology; See also: pituitary gland
prolyl oligopeptidase: An enzyme in the body that cuts short protein chains just after the amino acid proline. It is thought to release Ac-SDKP from thymosin beta-4.; Biology; See also: Ac-SDKP
proopiomelanocortin (POMC): A large protein the body cuts into several smaller hormones, including alpha-MSH and a stress hormone called ACTH.; Biology; See also: alpha-MSH
protease (proteases, peptidase, peptidases, proteolytic enzymes): An enzyme that cuts the bonds between amino acids. Proteases work in the gut, the blood and most tissues.; Biology; See also: peptide bond, pepsin, trypsin
protecting group (protecting groups, protected amino acids): A temporary chemical cap that stops part of an amino acid reacting at the wrong moment during synthesis. It is removed later.; Chemistry; See also: solid-phase peptide synthesis
protein (proteins): A long chain of amino acids, or several chains, folded into a fixed shape. Where a peptide ends and a protein begins is a convention, not a natural line.; Biology; See also: peptide, polypeptide
publication bias (file-drawer problem): The tendency for studies with positive results to be published more often than studies that found nothing. It makes treatments look better than they really are.; Research and evidence; See also: independent replication
PubMed: A free search engine for medical research papers, run by the US National Library of Medicine. It lists most studies in medicine and biology.; Research and evidence; See also: Embase
pulmonary aspiration (aspiration, aspiration pneumonia): When stomach contents flow back up and into the lungs. It is a known risk during general anaesthesia or deep sedation if the stomach is not empty.; Safety; See also: gastric emptying
pulsatile secretion (pulsatile, pulsatile release, hormone pulses, GH pulses, growth hormone pulses): Release of a hormone in short bursts instead of a steady flow. Growth hormone is released in pulses, many of them at night.; Biology; See also: growth hormone, negative feedback

Q

QT prolongation (prolonged QT, long QT, prolong the QT interval): A change in the heart's electrical rhythm, seen on a heart tracing (ECG). It can lead to a dangerous irregular heartbeat.; How drugs work in the body
quaternary structure: Two or more chains fitted together into one working unit.; Chemistry; See also: tertiary structure

R

racemisation (epimerisation, racemization, epimerization): An amino acid flipping into its mirror-image form during manufacture. It creates an impurity that looks almost the same as the wanted peptide.; Chemistry; See also: D-amino acid, impurity
radioimmunoassay (radioimmunoassays): A lab test that uses antibodies and a radioactive label to measure very small amounts of a hormone in the blood.; Biology
randomisation (randomization, random allocation, randomly assigned, randomly allocated): Deciding by chance, like a coin toss, who gets the treatment and who does not. It tends to make the groups alike in everything except the treatment, including things nobody measured. The bigger the groups, the better this works.; Research and evidence; See also: control group, allocation concealment
randomised controlled trial (randomised controlled trials, randomized controlled trial, randomized controlled trials, RCT, RCTs): A trial in which chance decides who gets the treatment and who gets a comparison, such as a dummy treatment. This makes it a fair test of whether the treatment itself causes the effect.; Research and evidence; See also: clinical trial, placebo
randomised withdrawal trial (randomized withdrawal trial, randomised withdrawal, randomized withdrawal): A trial in which everyone first takes the drug, and then some people are chosen at random to switch to placebo. It shows what happens when treatment stops.; Research and evidence
receptor (receptors): A protein on or in a cell that a hormone or medicine fits into, like a key in a lock. When it is switched on, the cell responds.; Biology; See also: G-protein-coupled receptor, agonist, antagonist
receptor internalisation (internalisation, internalization, receptor internalization): When a cell pulls a receptor from its surface into the inside of the cell. Fewer receptors on the surface means a weaker response to the drug or hormone.; Biology; See also: β-arrestin, desensitisation
receptor occupancy (predicted receptor occupancy): The share of receptors that a drug is bound to at a given moment. It is often estimated from drug levels in the blood rather than measured directly.; How drugs work in the body
recombinant (recombinant protein, genetically engineered): Made by cells, such as bacteria, that were given the gene for a human protein. The cells then produce the protein.; Chemistry
reconstitution (reconstitute, reconstituted, reconstituting): Dissolving a powdered medicine in a liquid so that it can be injected.; How drugs work in the body; See also: freeze-drying, sterile water for injection
recreational athlete (recreational athletes): Under the 2027 World Anti-Doping Code, an athlete below national level, as each national anti-doping organisation defines it. Lower bans are possible for them.; Sport; See also: NADO
regression to the mean: When something is measured at an unusually bad moment, the next measurement is likely to be closer to normal, even without treatment. People often seek treatment when symptoms are at their worst, so they tend to improve afterwards anyway.; Research and evidence; See also: placebo
relative risk (relative risks, relative risk reduction, risk ratio, risk ratios): A comparison of risk between two groups as a ratio or a percentage: "20% fewer". It does not tell you how common the problem was to begin with.; Research and evidence; See also: absolute risk, hazard ratio
renal infarction (kidney infarction, renal infarct): Death of part of a kidney because its blood supply is suddenly blocked, usually by a clot. It often causes sudden pain in the side or back.; Safety
research chemical (research chemicals, research use only, for research use only, not for human consumption): A label sellers put on products such as peptide vials. It does not make a product a licensed medicine, and it does not mean anyone checked that it is fit to inject.; Regulation; See also: marketing authorisation
reserved procedure (reserved procedures, reserved act, reserved acts, voorbehouden handeling, voorbehouden handelingen): A medical procedure, such as giving an injection, that Dutch law reserves for doctors and some other care professionals. Others may do it at work only on their instructions.; Law; See also: Wet BIG
responder analysis (responder analyses, anchor-based responder analysis): A way of reporting a trial by counting how many people improved by at least an amount judged to matter, instead of only the average change.; Research and evidence; See also: effect size
retraction (retracted, retracted paper): The formal withdrawal of a published paper by the journal, because its results can no longer be trusted.; Research and evidence; See also: expression of concern
rhabdomyolysis (muscle breakdown): A condition in which damaged muscle breaks down and releases a protein (myoglobin) into the blood that can harm the kidneys. Signs are muscle pain or weakness with dark, cola-coloured urine.; Safety
risk of bias (risk-of-bias assessment, risk-of-bias assessments): A structured check of how a study was done (randomisation, blinding, missing data, reporting) to judge how likely its result is distorted.; Research and evidence; See also: randomisation, blinding
RIVM (National Institute for Public Health and the Environment, Rijksinstituut voor Volksgezondheid en Milieu): The Dutch national institute for public health and the environment. This government institute gives advice on infections, hygiene and vaccines.; Regulation
rule of five (rule of 5): A rule of thumb from drug chemistry: a swallowed drug is less likely to be absorbed well if, among other things, it weighs more than 500 daltons.; How drugs work in the body; See also: dalton, bioavailability
rulemaking (notice-and-comment rulemaking, proposed rule, final rule): How a US agency makes a binding rule: it publishes a proposed rule, takes public comments, and then publishes a final rule.; Law; See also: Federal Register

S

S0 (non-approved substances) (S0, non-approved substances): The section of the WADA Prohibited List for substances that no government health regulator has approved as a medicine. They are banned in sport at all times, in and out of competition.; Sport
S2 (peptide hormones and growth factors) (section S2): The section of the WADA Prohibited List for peptide hormones, growth factors and similar substances. It names TB-500 and several growth-hormone peptides. They are banned at all times.; Sport; See also: Prohibited List, S2.3 (growth factors)
S2.3 (growth factors) (S2.3): The part of the WADA Prohibited List for growth factors and substances that change them, including thymosin beta-4 and TB-500. They are banned in sport at all times.; Sport
S4 (hormone and metabolic modulators) (section S4): The section of the WADA Prohibited List for substances that change hormones or metabolism. It names MOTS-c. They are banned at all times.; Sport; See also: Prohibited List
safety features (unique identifier, anti-tampering device, tamper seal): A unique code and a seal on the box of most prescription medicines in the EU. Pharmacies scan the code to check that the pack is genuine.; Safety; See also: falsified medicine
saline (saline solution): Sterile salt water with the same amount of salt as body fluids. Trials often inject it as a dummy treatment.; How drugs work in the body; See also: placebo
sample size (sample sizes, sample size calculation, number of participants): The number of people or animals in a study, often written as n. A good study works out in advance how many it needs.; Research and evidence; See also: statistical power
satisfying sexual event (satisfying sexual events, SSE, SSEs): In sexual-health trials, a sexual encounter that the participant herself rated as satisfying, counted in a diary.; Research and evidence; See also: Female Sexual Function Index
second messenger (second messengers): A small molecule made inside a cell when a receptor on the surface is switched on. It carries the message further into the cell. cAMP is one.; Biology; See also: cAMP, G-protein-coupled receptor
second opinion (second opinions): A check of your diagnosis or treatment plan by a second, independent doctor in the same field. In the Netherlands your doctor should normally refer you for one if you ask.; Law; See also: WGBO
second reading: A late stage in making an EU law. The European Parliament votes on the position the Council has taken on the text.; Law; See also: directive, EU regulation
secondary structure (helix, alpha-helix, beta-sheet): Local twists or pleats in a peptide chain, such as a spiral (helix) or a flat sheet, held mainly by hydrogen bonds.; Chemistry; See also: primary structure, tertiary structure, hydrogen bond
SEH (spoedeisende hulp): The hospital emergency department in the Netherlands. Unless a life is in danger, you go there only after the GP or huisartsenpost sends you.; Safety; See also: huisartsenpost, huisarts
selective outcome reporting (outcome switching, outcome reporting bias, selective reporting): Reporting the results that came out well and leaving out, or quietly changing, the ones that did not.; Research and evidence; See also: pre-registration, publication bias
selectivity (nonselectively, nonselective): A drug's preference for one target over others. It is never absolute: at higher amounts a drug acts on more targets.; How drugs work in the body; See also: off-target effect
self-doping: Using a banned substance or method on your own body to do better in sport. Some countries also punish it as a crime, not only through the sport rules.; Sport; See also: Prohibited List
senescence (cellular senescence, senescent): The state of a cell that has stopped dividing for good, for example because its telomeres have become too short. It is one of the body's brakes on cancer.; Biology; See also: telomere, telomerase
sepsis (blood poisoning, bloedvergiftiging): A life-threatening reaction to an infection, in which the body's response starts to damage its own organs. It needs hospital treatment straight away.; Safety; See also: cellulitis, lymphangitis
serious adverse event (serious adverse events, SAE, SAEs): A harmful event during a study that leads to death, danger to life, a hospital stay or lasting harm. It is counted whether or not the study drug caused it.; Research and evidence; See also: placebo
SGLT2 inhibitor (SGLT2 inhibitors): A diabetes tablet that makes the kidneys pass more sugar into the urine. Examples are dapagliflozin and empagliflozin.; How drugs work in the body
sharps container (sharps containers, sharps bin, naaldencontainer, needle container, needle box): A hard plastic box with a lid that closes tightly, for used needles. In the Netherlands you can get one at the pharmacy.; Safety; See also: needle-stick injury, klein chemisch afval
single-dose vial (single-dose vials, single-use vial, single-use vials): A vial meant to be opened once. It usually has no preservative, so whatever is left must be thrown away.; Safety; See also: multi-dose vial
sinoatrial node (sinus node): A small group of cells in the right upper chamber of the heart. It works as the heart's natural pacemaker and sets the heart rate.; Biology
six-minute walk test (6-minute walk test, 6MWT, 6-minute walk distance, 6MWD): A simple test of how far a person can walk in six minutes. Trials use it to measure fitness and stamina.; Research and evidence; See also: primary endpoint
small-molecule drug (small molecule, small molecules, small-molecule): A medicine made of a small chemical rather than a chain of amino acids. Most pills are small molecules.; How drugs work in the body; See also: peptide, dalton
SNAC (salcaprozate sodium, sodium N-[8-(2-hydroxybenzoyl)amino]caprylate): An ingredient in semaglutide tablets that helps a small part of the peptide pass through the stomach wall. Without it, almost none would be absorbed.; How drugs work in the body
solid-phase peptide synthesis (solid-phase synthesis, SPPS): The usual chemical way to make peptides: the chain is built on tiny resin beads, one amino acid at a time, with washing between steps.; Chemistry; See also: deletion sequence, protecting group
solvent (solvents, residual solvent, residual solvents): A liquid used to dissolve other substances while a medicine is made. Small amounts can stay behind in the product, so they are tested for.; Chemistry; See also: impurity
somatostatin: A natural peptide hormone that acts as a brake on the release of growth hormone and other hormones. It lasts only minutes in the blood.; Biology; See also: growth hormone, negative feedback
somatotroph (somatotrophs, somatotroph cells, somatotrope, somatotropes): A cell in the front part of the pituitary gland that makes and releases growth hormone.; Biology; See also: pituitary gland, growth hormone
somatropin (somatotropin, somatrem): Growth hormone made in a lab, used as a prescription medicine when the body makes too little. Somatotropin is the body's own hormone; somatrem was an older lab-made version.; How drugs work in the body; See also: growth hormone
special medicinal product (specials, special medicinal products): In the UK, an unlicensed medicine made or imported for one patient, ordered by a doctor or other prescriber for that patient's clinical needs.; Regulation; See also: unlicensed medicine, MHRA
specified substance (specified substances, non-specified substance, non-specified substances): In anti-doping rules, a banned substance that is more likely to have been taken for reasons other than sport. It is not less dangerous. The standard ban is shorter than for non-specified substances.; Sport; See also: Prohibited List, strict liability
spin (reporting spin): Wording that makes a result look better than the data show, for example highlighting a side result when the main result was negative.; Research and evidence; See also: p-value, primary endpoint
spinal fluid (cerebrospinal fluid, CSF): The clear fluid around the brain and spinal cord. In animal studies, drugs are sometimes injected into it to reach the nerves directly.; Biology; See also: blood-brain barrier
spleen: An organ on the left side of the belly, under the ribs. It filters the blood and helps the body fight infections.; Biology; See also: immune system
standard deviation score (SDS, SD score, standard deviation scores): A way to say how far a lab value is from the average for people of the same age and sex. A score above 2 is unusually high; above 3 is very high.; Research and evidence; See also: IGF-1
statistical power (underpowered, low power, well-powered): The chance that a study finds an effect if the effect is real. Small studies have low power: they miss real effects, and the effects they do find are often too large.; Research and evidence; See also: sample size, false positive
steady state (steady-state): The level a medicine settles at with regular use, when the amount removed between doses equals the amount given. It takes about four to five half-lives to get close.; How drugs work in the body; See also: half-life
sterile (sterility, sterilised, sterilized): Free of living germs. A needle or a liquid stays sterile only until it touches something that is not sterile.; Safety; See also: aseptic technique, freeze-drying
sterile abscess (sterile abscesses): An abscess with no germs in it. It is the body's reaction to something in the injected liquid itself. From the outside it looks like an infected abscess.; Safety; See also: abscess
sterile water for injection (water for injection, sterile water): Germ-free water made for dissolving medicines before injection. It has no preservative, so a container is used once and the rest is thrown away.; Safety; See also: bacteriostatic water, reconstitution
stimulant (stimulants): A drug that speeds up the brain and body, so you feel more awake and alert. Caffeine and amphetamine are stimulants.; How drugs work in the body
stopper (septum, rubber stopper, stoppers): The rubber top of a vial that the needle goes through. Wipe it with alcohol, let it dry, and do not touch it afterwards.; Safety; See also: aseptic technique
stratum corneum: The thin, tough outer layer of the skin. It is a barrier that keeps most large or water-loving molecules, including peptides, from passing into the body.; Biology
strict liability: The anti-doping rule that an athlete is responsible for any banned substance found in their body, whether or not they meant to take it.; Sport
study sponsor (trial sponsor, sponsored study, sponsored studies, industry-sponsored, industry sponsorship): The organisation that pays for and is responsible for a study, such as a company, a university or a government funder.; Research and evidence; See also: conflict of interest
subcutaneous (subcutaneously, subcutaneous injection, subcutaneous injections): Under the skin. A subcutaneous injection goes into the layer of fat just below the skin, not into a muscle or a vein.; How drugs work in the body; See also: lipohypertrophy, injection-site reaction
subgroup analysis (subgroup, subgroups): Looking at results for only part of the people in a trial, such as those treated early. A positive subgroup in a trial that missed its main goal can be chance.; Research and evidence; See also: primary endpoint
sublingual (under the tongue): Taken by letting it dissolve under the tongue, so that it is absorbed through the lining of the mouth.; How drugs work in the body; See also: intranasal
substantial evidence (substantial evidence of effectiveness): The proof US law asks for before a new medicine is approved: evidence from adequate and well-controlled studies that it does what its label claims.; Regulation; See also: adequate and well-controlled study, Kefauver-Harris Amendments
substudy (substudies, sub-study): A smaller study inside a larger trial, with extra tests in some of the trial's participants.; Research and evidence
sulfonylurea (sulfonylureas, sulphonylurea, sulphonylureas, gliclazide): An older group of diabetes tablets that make the pancreas release insulin even when blood sugar is normal. This is why they can cause low blood sugar.; How drugs work in the body
summary of product characteristics (SmPC, SPC, summaries of product characteristics): The official description of a licensed medicine for doctors and pharmacists. It lists what the medicine is for, the approved doses, side effects, warnings and interactions.; Regulation; See also: marketing authorisation
sun protection factor (SPF): A number that says how much longer protected skin can stay in the sun before it burns, compared with unprotected skin. SPF 2 means about twice as long.; Safety; See also: melanin
superagonist (superagonists): A molecule that switches a receptor on more strongly than the body's own signal does. TGN1412 was designed as one for a switch on T cells.; How drugs work in the body; See also: agonist, T cell
surrogate endpoint (surrogate endpoints, surrogate end point, surrogate end points, surrogate outcome, surrogate outcomes, surrogate marker): A measurement that stands in for what really matters, such as a blood value instead of heart attacks. It is quicker to measure, but improving it does not always help the patient.; Research and evidence; See also: clinical endpoint
sympathetic nervous system (sympathetic nerves, sympathetic activity): The part of the nervous system that prepares the body for action. It can narrow blood vessels and raise blood pressure.; Biology; See also: hypertension
sympathomimetic toxicity (sympathomimetic toxidrome, sympathomimetic excess, sympathomimetic symptoms, sympathomimetic reactions, sympathomimetic): Poisoning that over-activates the body's fight-or-flight system: a racing heart, high blood pressure, sweating, wide pupils, shaking and agitation.; Safety; See also: sympathetic nervous system, rhabdomyolysis
syringe units (insulin syringe, insulin syringes, units on an insulin syringe): The marks on an insulin syringe. They measure an amount of liquid, made to fit insulin. They do not show how much of any other substance is in that liquid.; Safety; See also: hypoglycaemia
systematic review (systematic reviews): A review that searches for every study on a question with a method set in advance, judges each study's quality and sums up the whole body of evidence.; Research and evidence; See also: meta-analysis, narrative review
systolic blood pressure (systolic, diastolic blood pressure, diastolic, mmHg): Blood pressure has two numbers. The top (systolic) number is the pressure when the heart pumps; the bottom (diastolic) number is the pressure between beats. Both are measured in mmHg.; Safety; See also: hypertension, ambulatory blood pressure monitoring

T

T cell (T cells, T-cell, T-cells, T lymphocytes): A type of white blood cell that directs and carries out immune responses.; Biology; See also: cytokine storm
tachycardia (fast heart rate): A heart rate at rest that is faster than normal, usually more than 100 beats a minute in adults.; Safety; See also: palpitations
telomerase: An enzyme that rebuilds telomeres. Most body cells keep it switched off; many cancer cells switch it on, which helps them keep dividing.; Biology; See also: telomere
telomere (telomeres): The protective caps at the ends of chromosomes. In most body cells they get a little shorter every time the cell divides.; Biology; See also: telomerase
teratogen (teratogens, teratogenic, teratogenesis): A substance that can harm an unborn baby while its body is forming, causing birth defects.; Safety; See also: thalidomide
tertiary structure: The overall three-dimensional fold of a whole chain, held by contacts between its side chains and sometimes by sulfur bridges.; Chemistry; See also: secondary structure, quaternary structure, disulfide bond
testing pool (registered testing pool): A group of top athletes who must say where they are, so they can be tested without warning, also outside competitions.; Sport; See also: NADO
tetrapeptide (tetrapeptides): A peptide made of exactly four amino acids joined in a chain. Epitalon is a tetrapeptide.; Chemistry
thalidomide (Softenon, Contergan, Distaval): A sleeping pill sold from the late 1950s and given for morning sickness. Taken early in pregnancy, it caused severe birth defects in more than 10,000 children.; Safety; See also: teratogen, Kefauver-Harris Amendments
Therapeutic Use Exemption (TUE, TUEs, medical exemption, medical exemptions): Permission from an anti-doping organisation for an athlete to use a banned substance for a medical reason. Four strict tests must all be met.; Sport; See also: Prohibited List, WADA
Thuisarts (Thuisarts.nl): A Dutch website with health advice for patients, written by the Dutch College of General Practitioners (NHG).; Safety; See also: NHG, huisarts
thymosin beta-4 (thymosin β4, Tβ4, Tbeta4, thymosin beta 4, timbetasin): A natural protein of 43 amino acids found inside many kinds of cells. It holds single actin units ready for use. It is not the same substance as TB-500.; Biology; See also: actin, heptapeptide
thymus (thymus gland, thymic): A small organ behind the breastbone where T cells, a kind of white blood cell, learn their job. It shrinks with age.; Biology; See also: T cell
thyroid C-cells (C-cells, C-cell, parafollicular cells, calcitonin): A small group of cells in the thyroid gland that make the hormone calcitonin. In rats and mice they carry many GLP-1 receptors; in people they carry few.; Biology; See also: medullary thyroid carcinoma
tight junction (tight junctions): A seal between neighbouring cells of a lining, such as the gut wall. It keeps large molecules from slipping between the cells.; Biology; See also: brush border
tissue (tissues): A group of similar cells that do one job together in the body, such as muscle, skin, fat or tendon.; Biology
tolerance (to a drug) (drug tolerance, tolerance effect): A weaker response to a drug after repeated or long use, for example because cells have fewer working receptors.; How drugs work in the body; See also: desensitisation, receptor internalisation
toll-like receptor (toll-like receptors, TLR, TLRs): A sensor on immune cells that recognises common features of germs and switches on an immune response.; Biology; See also: dendritic cell
topline results (topline, top-line results, topline data): The first headline numbers from a trial, released by the company before independent experts have checked the full results.; Research and evidence; See also: peer review
toxicity study (toxicity studies, toxicity test, toxicity tests): A test, usually in animals, that looks for harm from a substance, for example to the liver, the kidneys or the blood. Such tests are done before a new medicine is first given to people.; Research and evidence; See also: genotoxicity
toxin (toxins, bacterial toxin, bacterial toxins): A poison made by a living thing, such as bacteria. Some bacterial toxins stay in a product even after the germs themselves have been killed.; Safety; See also: endotoxin
transcription factor (transcription factors): A protein inside the cell that switches particular genes on or off.; Biology
translational research (animal-to-human translation, translational): The work of carrying a finding from cells or animals into tested treatments for people, and the study of how often that succeeds.; Research and evidence; See also: animal model, first-in-human trial
trial phase (phase 1, phase 1b, phase 2, phase 2a, phase 3, trial phases): The steps of testing a new medicine in people. Phase 1 checks safety in a few dozen people, phase 2 tests doses in hundreds, and phase 3 confirms benefits and harms in thousands.; Research and evidence; See also: investigational medicine
trifluoroacetate salt (TFA salt, TFA, trifluoroacetate): A salt form of a peptide made with trifluoroacetic acid, often left over from lab synthesis. It is a different substance from the free base or the acetate salt.; Chemistry; See also: free base
trigeminal neuralgia: Sudden attacks of severe pain on one side of the face, coming from the nerve that carries feeling from the face.; Biology
triglycerides (triglyceride, blood fats): The main type of fat in the blood. High levels over a long time raise the risk of heart and blood-vessel disease.; Biology
tripeptide (tripeptides): A peptide made of exactly three amino acids joined in a chain. KPV is a tripeptide: lysine, proline and valine.; Chemistry
triple agonist (triple agonists, triple agonism, triple hormone receptor agonist, triple-hormone-receptor agonist, tri-agonist): One drug molecule that switches on three different receptors. Retatrutide switches on the receptors for GIP, GLP-1 and glucagon.; How drugs work in the body; See also: agonist, dual agonist
trough level (trough levels, trough, troughs, low points between pulses): The lowest level of a hormone or medicine in the blood, between its peaks.; How drugs work in the body; See also: pulsatile secretion
trypsin (chymotrypsin, elastase, carboxypeptidase, carboxypeptidases): One of several protein-cutting enzymes that the pancreas releases into the small intestine to digest food protein.; Biology; See also: pepsin, protease
tuftsin: A natural chain of four amino acids cut from an antibody. It stirs up immune cells that eat germs. Selank is built on it.; Biology
tumour (tumours, tumor, tumors): A lump of cells that keep dividing when they should not. A tumour can be harmless (benign) or a cancer that can spread (malignant).; Biology
tyrosinase: The enzyme in pigment cells that starts turning the amino acid tyrosine into melanin.; Biology; See also: melanin, melanocyte

U

UK Anti-Doping (UKAD): The national anti-doping organisation of the United Kingdom. It tests athletes and applies the World Anti-Doping Code in the UK.; Sport; See also: NADO, WADA
ulcer (ulcers, leg ulcer, leg ulcers, foot ulcer, foot ulcers): An open sore on the skin, or on the inside lining of an organ such as the stomach, that heals slowly.; Biology
ulcerative colitis: A long-term inflammatory disease of the large bowel. It causes bloody diarrhoea and can lead to serious complications, so it needs medical treatment.; Biology
ultraviolet light (UV, UV light, UVA, UVB, ultraviolet radiation, UV radiation): Light from the sun and from sunbeds that the eye cannot see. UVB burns the skin; UVA goes deeper. Both can damage the DNA in skin cells and lead to skin cancer.; Biology; See also: melanin, sun protection factor
umbrella review (umbrella reviews): A review of systematic reviews: it collects many reviews on related questions and compares what they found.; Research and evidence; See also: systematic review
unapproved new drug (unapproved new drugs): In US law, a drug that experts do not generally recognise as safe and effective for its use, and that the FDA has not approved. It may not be sold across state lines.; Law; See also: Federal Food, Drug, and Cosmetic Act, interstate commerce
unlicensed medicine (unlicensed medicines, unlicensed medicinal product, unlicensed medicinal products): A medicine that has no licence (marketing authorisation) in the country where it is sold. Its safety, effect and quality have not been assessed there.; Regulation; See also: marketing authorisation, special medicinal product
user fees (user fee, Prescription Drug User Fee Act, PDUFA): Fees that companies pay the US FDA when they apply for approval. Since 1992 they pay for extra reviewers, in return for goals for how fast reviews are done.; Regulation; See also: FDA

V

vasoconstriction (vasospasm, coronary vasospasm): Narrowing of a blood vessel. When the heart's own arteries narrow, less blood reaches the heart muscle.; Biology
VEGF (vascular endothelial growth factor): A growth signal that tells the cells lining blood vessels to grow and form new vessels. Healing tissue and many tumours release it.; Biology; See also: VEGFR2, angiogenesis
VEGFR2 (VEGFR-2, VEGF receptor 2, vascular endothelial growth factor receptor 2): A receptor on the cells that line blood vessels. When the growth signal VEGF binds to it, these cells divide and move, and new vessels can form.; Biology; See also: angiogenesis
venous leg ulcer (venous leg ulcers, venous ulcer, venous ulcers, venous stasis ulcers): An open wound on the lower leg that does not heal for weeks or months. It is caused by poor blood flow back to the heart through the leg veins.; Biology
vial (vials): A small glass bottle closed with a rubber stopper. A needle is pushed through the stopper to draw up the liquid.; Safety; See also: stopper, single-dose vial, multi-dose vial
visceral fat (visceral adipose tissue, VAT, deep belly fat, abdominal visceral fat): Fat stored deep inside the belly, around the organs. It is different from the fat just under the skin.; Biology; See also: lipodystrophy, lipolysis
vitiligo: A condition in which the skin loses its pigment cells in patches, so those areas turn white.; Biology; See also: melanocyte
volume of distribution: A measure of how far a medicine spreads from the blood into the tissues. It is a calculated number, not a real space in the body.; How drugs work in the body; See also: pharmacokinetics

W

WADA (World Anti-Doping Agency): The World Anti-Doping Agency. Each year it publishes the list of substances that are banned in sport.; Sport; See also: S0 (non-approved substances), strict liability
WADA Monitoring Program (Monitoring Program, monitoring programme): A list of substances that are not banned in sport but that the World Anti-Doping Agency tests for, to see whether athletes misuse them.; Sport
warning letter (warning letters): A public letter from the FDA telling a company that it is breaking the law and must fix it. If it does not, the FDA can take further steps, such as seizing products.; Regulation; See also: FDA
weakened immune system (weak immune system, immunosuppression, immunosuppressed, immunosuppressants): When the body's defence against germs works less well, for example because of HIV, chemotherapy, steroids or medicines that suppress the immune system. Infections are then more likely and more dangerous.; Biology; See also: sepsis
Wet BIG (BIG Act, Individual Health Care Professions Act): The Dutch law on health care professions. It says who may use titles such as doctor or nurse, and who may do risky procedures such as injections.; Law; See also: reserved procedure
Wet op de Geneesmiddelenvoorziening: The Dutch medicines law of 1958. It set up a board that registered packaged medicines. The Geneesmiddelenwet replaced it on 1 July 2007.; Law; See also: Geneesmiddelenwet, CBG
WGBO (Medical Treatment Contracts Act, Wet op de geneeskundige behandelingsovereenkomst): The Dutch law on medical treatment, part of the Civil Code. It sets out your rights as a patient: information, consent, privacy and access to your medical file.; Law; See also: informed consent, medical confidentiality, medical file
World Anti-Doping Code (WADA Code, Anti-Doping Code): The rulebook that WADA and sport bodies around the world follow. It sets how athletes are tested, what counts as a doping offence and which bans follow.; Sport; See also: WADA, Prohibited List, strict liability
World Health Organization (World Health Organisation): The United Nations agency for health. Health services around the world use its guidance, for example on safe injections.; Regulation

Y

Yellow Card (Yellow Card scheme): The UK system for reporting side effects and problems with medicines. It is run by the UK medicines regulator, the MHRA, and anyone can use it.; Regulation

Z

zeranol: A substance that acts like the hormone oestrogen. Some countries outside the EU give it to cattle to make them grow faster; the EU does not allow this.; How drugs work in the body; See also: anabolic agent
zilpaterol: A substance added to cattle feed in some countries, so that the animals put on more lean meat before slaughter. The EU does not allow it.; How drugs work in the body; See also: anabolic agent
Zorginstituut Nederland (Zorginstituut, National Health Care Institute): The Dutch body that advises which care and medicines basic health insurance should pay for.; Regulation

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