Incretin (GLP-1 family)

Semaglutide

A prescription medicine for type 2 diabetes and weight management. Online “research” vials are not the same.

Authorised medicine

At a glance

Is it an approved medicine?: Yes. Approved in the EU. Only with a doctor’s prescription.
Has it been tested in people?: Yes. Large trials in many people, checked by regulators.
Is it allowed in sport?: Not banned. It is not on the anti-doping list.
What is the biggest risk?: Many feel sick at first. Gallstones and an inflamed pancreas are rarer. More about the risks

Status checked on 20 October 2026. The details and sources are further down this page.

Stop and get help if you notice

Severe belly pain, often spreading to your back³
Shaky, sweaty or confused (low blood sugar)^3,7
Swollen face or throat, or trouble breathing³

If it is severe, call your local emergency number.

All warning signs, further down this page Warning signs for any peptide

The 30-second version

About 7 minutes for the short version; 39 with every detail open.

Semaglutide is an authorised EU medicine. Ozempic and Rybelsus treat type 2 diabetes. Wegovy helps manage weight.
It copies a gut hormone called GLP-1. It lowers high blood sugar and makes you feel full sooner.
Large trials show lower blood sugar and weight. Some groups also had fewer serious heart and kidney problems.
Stomach problems are common at first. Rarer risks include gallstones, pancreatitis and a rare eye condition. Much of the lost weight comes back after stopping.
Online 'research' semaglutide is not the authorised medicine. Nobody knows what is in it, or how much.

Class: Incretin (GLP-1 family)
How it is taken: Injection under the skin, or a tablet
How often: Injection once a week; tablet once a day
How long it lasts: Half-life about one week; stays 5–7 weeks after stopping
Status in the EU: Authorised since 2018
Tested in people: Yes

Label facts, not dosing advice. Sources are in the sections below.

Last reviewed: 20 October 2026

A Gila monster, a heavy lizard with beaded black and orange-pink skin, walking over red rocks and dry grass at night. — A Gila monster. Its venom led to a drug that works like semaglutide, which copies a human hormone. Photo: Jeff Servoss, U.S. Fish and Wildlife Service (Wikimedia Commons) Public domain Image details

Each section starts with the short answer. The rest is folded under “In detail”.

Show all details

Evidence profile

Four separate questions. Not a score.

Human clinical evidence How far has it been tested in people?: Authorised by a regulator (step 6 of 6); None published
Case reports only
Phase I (safety, small)
Phase II (dose and early effect)
Phase III (large controlled trials)
Authorised by a regulator
Preclinical volume How much laboratory and animal research exists?: Extensive (step 3 of 3); Minimal
Moderate
Extensive
Source independence How many independent groups produced it?: Broadly replicated (step 3 of 3); One group dominates
A few groups
Broadly replicated
Safety characterisation How well do we know the harms in humans?: Well characterised (step 3 of 3); Uncharacterised
Partial
Well characterised

In detail Why these grades: the reason for each step

Human clinical evidence: Authorised in the EU since 2018 (Ozempic), with Rybelsus (2020) and Wegovy (2022; tablets 2026). The authorisations rest on phase 3 programmes and several completed cardiovascular and kidney outcome trials, each with thousands of participants.
Preclinical volume: Well over 50 primary animal and cell studies: a PubMed search on 20 October 2026 found 472 non-review records mentioning semaglutide together with rats or mice in the title or abstract. The animal record now matters mainly for the thyroid C-cell and pregnancy findings.
Source independence: Every pivotal trial was paid for by the manufacturer, and many authors were company employees. The weight effect has been seen without company authors too (a Mayo Clinic cohort), and the main safety signals (NAION, thyroid cancer, suicidal thoughts) were tested by independent academic groups and regulators.
Safety characterisation: Characterised in randomised trials with tens of thousands of participants followed for up to about four years, plus post-marketing surveillance since 2017–2018. Still being worked out: NAION, use beyond a few years, stopping and restarting, effects on muscle, exposure in pregnancy, and the newer high-strength dose.

We never add these up. A compound can have a large animal literature from one laboratory and no human data at all — that is a specific situation, and a single number would hide it. How we grade evidence

In detail The molecule: amino-acid sequence and technical details

Amino-acid sequence31 amino acids

H–His-Aib-Glu-Gly-Thr-Phe-Thr-Ser-Asp-Val-Ser-Ser-Tyr-Leu-Glu-Gly-Gln-Ala-Ala-Lys*-Glu-Phe-Ile-Ala-Trp-Leu-Val-Arg-Gly-Arg-Gly–OH (*side chain on Lys)

Read from the N-terminus (start) to the C-terminus (end).

Modifications: position 2: Aib (GLP-1 position 8): replaces Ala of human GLP-1; stabilises the peptide against DPP-4 cleavage; position 20: Lys (GLP-1 position 26): ε-amine carries 2×OEG (8-amino-3,6-dioxaoctanoyl) – γGlu – 17-carboxyheptadecanoyl (C18 fatty diacid); drives albumin binding; position 28: Arg (GLP-1 position 34): replaces Lys of human GLP-1 so only one lysine is left for the fatty-acid side chain
non-standard amino acid: Aib (2)

International non-proprietary name: semaglutide
Also called: NN9535, NNC 0113-0217
Authorised products: Ozempic, Wegovy, Rybelsus
Class: Incretin (GLP-1 family)
Body systems: Metabolism, Hormones, Heart and blood vessels, Gut, Kidneys
Formula: C₁₈₇H₂₉₁N₄₅O₅₉
Molecular mass: 4,113.58 Da

What it actually is

What is semaglutide?

A medicine on prescription that copies a gut hormone. Online vials with this name are a different product.

A pharmacy medicine and an online vial with the same name are not the same thing. What is known about each, from the regulators’ assessments and warnings.

	Authorised medicine (Ozempic, Rybelsus, Wegovy)	Outside the legal supply chain (online “research” vial, unlicensed pen)
Checked by a regulator?	Yes Assessed before authorisation^1,2,3	No Powder-in-vial GLP-1 products are not authorised⁴
Contents known?	Yes Assessed by the regulator	No You do not know what is in it⁵; fake pens containing insulin have been found^6,7
Amount per dose known?	Yes Fixed by the pen or tablet	No Depends on your own measuring⁸
Made sterile?	Yes Made by a manufacturer named in the authorisation, which releases each batch³	Unknown Quality not known⁹
Risk information kept up to date?	Yes Official label, updated³	No None: how to use it, and what it does to your health, is unclear⁵
Someone to ask, and medical follow-up?	Yes Prescriber and pharmacist⁵	No No one

In detail The authorised products, and why this page looks different

Semaglutide is a prescription medicine. In the EU it is authorised as Ozempic (weekly injection for type 2 diabetes, since 8 February 2018), Rybelsus (daily tablet for type 2 diabetes, since 3 April 2020) and Wegovy (weight management: weekly injection since 6 January 2022, daily tablet since 14 July 2026).^1,2,3,10 The marketing authorisation holder is Novo Nordisk A/S.

Authorised medicine

A regulator has assessed this medicine's quality, efficacy and safety for specific uses. That applies to the authorised product from a pharmacy — not to vials sold online under the same chemical name.

The legal route

In the Netherlands this medicine is prescription-only. A doctor decides whether it suits you and at what dose; a pharmacy supplies the authorised product. Legal routes explained

Authorised products
Product	Authorised for	Where	Authorised since	Official product information
OzempicNovo Nordisk A/S	Adults with type 2 diabetes that is not well controlled, alongside diet and exercise: on its own when metformin is unsuitable, or added to other diabetes medicines. · Injection under the skin	European Union	8 February 2018	Product information (EU) (opens an external site)
RybelsusNovo Nordisk A/S	Adults with type 2 diabetes that is not well controlled, alongside diet and exercise: on its own when metformin is unsuitable, or with other diabetes medicines. A daily tablet. · Tablet	European Union	3 April 2020	Product information (EU) (opens an external site)
Wegovy (injection)Novo Nordisk A/S	Weight management alongside a reduced-calorie diet and more physical activity: adults with a BMI of 30 or more, or 27 to 30 with at least one weight-related condition; adolescents from 12 years with obesity and body weight above 60 kg. · Injection under the skin	European Union	6 January 2022	Product information (EU) (opens an external site)
Wegovy (tablets)Novo Nordisk A/S	Weight management in adults only, alongside a reduced-calorie diet and more physical activity: BMI of 30 or more, or 27 to 30 with at least one weight-related condition. · Tablet	European Union	14 July 2026	Product information (EU) (opens an external site)

In detail The molecule, where it came from, and the tablet

What the molecule is

Semaglutide is a chain of 31 amino acids. Twenty-nine are the same as in human GLP-1 (7–37), the active form of a hormone the gut releases after a meal; the EU label calls this 94% sequence homology.³ The chain starts His-Aib-Glu-Gly-Thr-Phe.

Three changes make the hormone last a week. Positions use the GLP-1 (7–37) numbering of the literature and the US label, in which the first histidine is position 7.^11,12,13

Position 8: alanine is replaced by Aib (2-aminoisobutyric acid), which stabilises the peptide against the enzyme DPP-4.
Position 34: lysine is replaced by arginine, so only one lysine is left for the side chain.
Position 26: that lysine carries two short hydrophilic spacers, a glutamic-acid linker and an 18-carbon fatty diacid. This part binds to albumin in the blood.

The formula is C187H291N45O59 and the molecular mass 4113.58 g/mol; the US label states that the peptide backbone is produced by yeast fermentation.¹¹

Where it came from

In 1987 three groups showed that a gut fragment of proglucagon releases insulin: in the pig pancreas, the rat pancreas and seven human volunteers, in whom an infusion raised insulin and lowered glucose and glucagon (Evidence level: Seen in humans in case reports or small uncontrolled studies).^14,15,16 In 1993 a GLP-1 infusion normalised fasting glucose in 10 people with type 2 diabetes, and insulin fell back once glucose was normal (Evidence level: Seen in humans in case reports or small uncontrolled studies).¹⁷ But the natural hormone lasts about 1–2 minutes, because DPP-4 cuts it and the kidneys clear it.¹⁸ In a study of 8 people with type 2 diabetes and 8 healthy volunteers, most of the GLP-1 measured in blood 30 minutes after an injection under the skin was already the cut, largely inactive form.^19,18 An earlier analogue, liraglutide, used a fatty-acid side chain and was given daily; semaglutide was designed for stronger albumin binding and full stability against breakdown.¹²

Injection and tablet

Peptides are digested in the gut, so most are injected. Semaglutide tablets contain an absorption enhancer, SNAC (salcaprozate sodium); in dogs and people, absorption took place in the stomach, next to the dissolving tablet (Evidence level: Seen in humans in case reports or small uncontrolled studies).²⁰ Only about 1–2% of the dose is absorbed, varying widely between people, so tablet strengths are much higher than injection strengths; the EU label states that the effect of switching between tablets and injections cannot easily be predicted.²

In detail Why “semaglutide” is not one thing

The evidence on this page belongs to manufactured products: a known substance in a pen or tablet that delivers a fixed amount, with a label updated as new risks are found. A vial sold online as “research semaglutide” shares the name, but none of the guarantees that let that evidence apply: known content, a fixed dose, sterility and an updated label.⁹

Lumping authorised GLP-1 medicines together with grey-market peptides misleads in two directions:

It flatters the experimental peptides. “Ozempic works and it is a peptide, so the other peptides probably work too.” Semaglutide’s evidence comes from its own trials in tens of thousands of people, not from being a peptide; most peptides sold alongside it have no comparable trial.
It undersells the medicine and oversells the vial. “It is all grey-market peptide stuff” can put people off a medicine that, in specific groups, lowered the combined risk of heart attack, stroke or cardiovascular death, and of serious kidney events, in large trials, while inviting them to treat an online vial as if it carried that safety record. It does not.

The comparison at the top of this section sets out the differences row by row.

How it works

What does it do in the body?

It raises insulin when blood sugar is high, lowers hunger and, at first, slows the stomach.

The short animation shows where semaglutide acts in the body, one step at a time.

Animation · 25 seconds How semaglutide works in the body

In detail Organ by organ: what it does in each place, and how well that is shown

The figure shows first how semaglutide works in a single cell, then what happens in each organ. In a body scan study of 140 people in STEP 1, fat fell more than lean mass, and most of the weight lost was fat.³

Figure · organ by organ Semaglutide acts on one receptor. What happens depends on the organ. How it works in one cell, then in each organ, and how well each effect is shown.

In detail Body map: three places where it acts

In detail Step by step: the chain of effects and its evidence

Semaglutide switches on the GLP-1 receptor and keeps doing so for days. Most effects, wanted or unwanted, follow from where that receptor is found. The numbered chain below gives each step of the animation in more detail, with the evidence behind it.

The proposed causal chain, step by step

Each step is labelled with how well the link from the previous step is established.

Step 1 Binding How well this link is shown: In humans

Engineered to last about a week

Natural GLP-1 is cut by the enzyme DPP-4 and cleared by the kidneys within about 1–2 minutes. Semaglutide has Aib instead of alanine at position 8, which protects it from DPP-4, and a fatty-acid side chain on lysine 26 that binds loosely to albumin. Bound to albumin it escapes kidney filtration, so its elimination half-life in people is about one week.
Step 2 Binding How well this link is shown: In cells

Activates the GLP-1 receptor

Semaglutide binds the same receptor as natural GLP-1, a G-protein-coupled receptor found on pancreatic beta cells, in several brain areas, and in the heart, blood vessels, immune cells and kidneys. Its receptor affinity was measured in cell systems; it is about three times lower than liraglutide's, a trade-off accepted for stronger albumin binding.
Step 3 Signal inside the cell How well this link is shown: In cells

Gs protein switches on cAMP

The activated receptor couples to the Gs protein and adenylate cyclase, so cAMP rises inside the cell. In beta cells, cAMP acting through PKA and Epac2 amplifies insulin release that glucose has already triggered. This is shown in cell lines and animal islets, not measured directly in human pancreas.
Step 4 Cell response How well this link is shown: In humans

More insulin and less glucagon, mainly when glucose is high

Because cAMP amplifies rather than starts insulin release, the extra insulin comes mainly when blood glucose is raised. In a 12-week randomised trial in 75 people with type 2 diabetes, insulin secretion rose and glucagon fell. The EU label states that during low blood glucose semaglutide reduces insulin secretion and does not impair glucagon release, which is why its own risk of hypoglycaemia is low (but not zero).
Step 5 Tissue response How well this link is shown: In humans

Less hunger, more fullness

In rodents, semaglutide reaches the hindbrain and hypothalamus through areas where the blood–brain barrier is open; it does not cross the barrier itself. In a 20-week trial in 72 adults with obesity, people took in 35% fewer calories than with placebo at a free-choice lunch and reported less hunger and fewer cravings. The human brain sites are inferred from animal work.
Step 6 Tissue response How well this link is shown: In humans

Slower stomach emptying, mostly early on

GLP-1 slows the stomach. Semaglutide delays emptying in the first hour after a meal; with continued weekly use the effect appears to fade, which the EU label attributes to tolerance (no clear delay was found at week 20 in the appetite trial). The early effect adds to nausea and is why tablets taken at the same time, and anaesthesia, need thought.
Step 7 Effect on the body How well this link is shown: In humans

Lower HbA1c and weight; fewer heart and kidney events in outcome trials

In trials the combined result is lower HbA1c, weight loss and, in outcome trials, fewer heart attacks, strokes, cardiovascular deaths and kidney events in the groups studied. How much of the heart and kidney benefit comes through weight and glucose, and how much through other effects, has not been established.

What each step rests on

Staying in the blood. The EU label gives a half-life of about one week and more than 99% albumin binding, measured in people.³ The chain is mechanical: albumin is too big for the kidneys to filter, so only the small free fraction is cleared, and Aib at position 8 protects against DPP-4. Semaglutide therefore stays in the circulation for about five to seven weeks after the last dose; side effects do not end the day you stop.^3,2

Receptor and cAMP. Semaglutide is a direct agonist at the GLP-1 receptor, with an affinity measured in cell systems.^24,12 The activated receptor switches on adenylate cyclase, so cAMP rises inside the cell; in beta cells, cAMP acts through PKA and Epac2 to increase insulin release.¹⁸ This chain is established in cell lines and animal islets (Evidence level: Shown in cells or tissue in the laboratory), not traced step by step in human pancreas.

Why the insulin effect depends on glucose. cAMP amplifies an insulin release that glucose has already triggered; it does not start one. In a 12-week, manufacturer-funded, double-blind, placebo-controlled trial in 75 people with type 2 diabetes, semaglutide increased insulin secretion and lowered glucagon after meals (Evidence level: Shown in controlled human trials).²¹ The EU label adds that during hypoglycaemia semaglutide reduces insulin secretion and does not impair glucagon release.³ That is why its own risk of low blood sugar is low, and why much of that protection is lost when it is combined with medicines that raise insulin regardless of glucose.

Appetite. In rodent experiments by the manufacturer, semaglutide reached the brainstem and hypothalamus through regions where the blood–brain barrier is open, and activated areas thought to be involved in ending a meal (Evidence level: Shown in animal studies).²² In a manufacturer-funded, double-blind, randomised trial in 72 adults with obesity, 20 weeks of semaglutide cut energy intake at a free-choice lunch by 35% compared with placebo, with less hunger and fewer cravings (Evidence level: Shown in controlled human trials).²³ The eating effect is measured in people; the brain sites are inferred from animals.

The stomach. GLP-1 slows stomach emptying.¹⁸ The EU label describes a minor delay early after a meal, and no clinically relevant effect at the 2.4 mg strength, probably because of tolerance; the appetite trial found no clear delay at week 20.^3,23

What the mechanism does not explain

The heart and kidney benefits are real in the populations studied but only partly explained: the EU label calls the cardiovascular benefit likely multifactorial, in part driven by weight loss and by effects on blood pressure, lipids, glucose and inflammation, and states that “the exact mechanism of cardiovascular risk reduction has not been established”.³

What the evidence actually shows

Does it work?

Yes, for blood sugar and weight. Some groups also had fewer serious heart and kidney problems.

Weight fell by about 15% on average

14.9%

average weight lost in 68 weeks, against 2.4% with placebo

Who took part STEP 1: 1,961 adults with obesity or overweight, without diabetes Source Wilding et al. (2021)²⁵ Evidence Established

Fewer heart attacks, strokes and heart deaths

6.5 in 100

had one in about 3 years, against 8 in 100 on placebo

Who took part SELECT: 17,604 adults with heart or blood-vessel disease and obesity or overweight, without diabetes Source Lincoff et al. (2023)²⁶ Evidence Human trials

Serious kidney problems: less often than on placebo

24%

less often: kidney failure, kidney function halved, or kidney or heart death

Who took part FLOW: 3,533 people with type 2 diabetes and chronic kidney disease Source Perkovic et al. (2024)²⁷ Evidence Human trials

About two-thirds of the lost weight came back within a year of stopping

2 in 3

of the kilos lost had come back, on average, a year after stopping

Who took part STEP 1 extension: 327 people followed for a year after stopping Source Wilding et al. (2022)²⁸ Evidence Human trials

In detail Every key study in one table

18 studies: 15 in humans, 2 in animals, 0 in cells, 1 reviews or other.

Studies discussed on this page
Study	Species	n	Design	Funding	Research group	What it found	What it did not show
Kreymann et al. 1987 ¹⁶	Humans	7	Randomised controlled trial (controlled)	Not disclosed	Independent group	GLP-1 (7-36) was found in the human gut and rose in blood after a meal. Infused into seven volunteers at meal-like levels, it raised insulin and lowered glucose and glucagon, more strongly than GIP.	A small physiological study of the natural hormone, not of semaglutide; short infusions; a handful of healthy volunteers.
Bjerre Knudsen et al. 2010 ⁷¹	Mixed	not reported	Animal experiment (controlled)	Industry	Originating group	Rat and mouse thyroid C-cells carry GLP-1 receptors; GLP-1 agonists raised calcitonin and caused C-cell hyperplasia in rodents. Human and monkey C-cells had low receptor levels, and liraglutide for 20 months in monkeys caused no C-cell hyperplasia.	Studied liraglutide, not semaglutide; run by the manufacturer; the authors state the long-term human consequences remain unknown.
Lau et al. 2015 ¹²	Mixed	not reported	Animal experiment	Industry	Originating group	Describes how semaglutide was chosen: two amino-acid substitutions (Aib8, Arg34) and a fatty-acid side chain on Lys26 for albumin binding. Plasma half-life was 46.1 hours after intravenous dosing in mini-pigs.	Medicinal chemistry and animal pharmacokinetics from the developer; human half-life comes from later clinical studies.
Marso et al. 2016 ³⁰	Humans	3,297	Phase III trial (controlled, blinded)	Industry	Originating group	In 3,297 people with type 2 diabetes at high cardiovascular risk, followed for 104 weeks, heart attack, stroke or cardiovascular death occurred in 6.6% with semaglutide and 8.9% with placebo (HR 0.74). Diabetic retinopathy complications were more frequent (HR 1.76).	Designed to rule out harm (non-inferiority), not to prove benefit; relatively few events; two years only.
Buckley et al. 2018 ²⁰	Mixed	not reported	Pharmacokinetic study	Industry	Originating group	In dogs and people, oral semaglutide co-formulated with SNAC was absorbed in the stomach, close to the dissolving tablet, through the cells rather than between them.	Mechanistic work by the developer; explains why absorption is low and variable but does not measure clinical outcomes.
Aroda et al. 2019 ²⁹	Humans	703	Phase III trial (controlled, blinded)	Industry	Originating group	In 703 adults with type 2 diabetes on diet and exercise alone, daily oral semaglutide lowered HbA1c against placebo at all three strengths tested over 26 weeks.	26 weeks; glucose and weight endpoints only; it used the original tablet formulation, which the EU label states is bioequivalent to the current tablets.
Husain et al. 2019 ³¹	Humans	3,183	Phase III trial (controlled, blinded)	Industry	Originating group	In 3,183 people with type 2 diabetes at high cardiovascular risk, followed for a median of 15.9 months, major cardiovascular events occurred in 3.8% with oral semaglutide and 4.8% with placebo (HR 0.79, 95% CI 0.57–1.11).	A safety trial: it ruled out a large increase in risk but was too short and small to show a reduction.
Friedrichsen et al. 2021 ²³	Humans	72	Randomised controlled trial (controlled, blinded)	Industry	Originating group	In 72 adults with obesity treated for 20 weeks, energy intake at a free-choice lunch was 35% lower than with placebo; hunger and cravings fell. No clear delay in gastric emptying was found at week 20.	Small, short, manufacturer-funded; gastric emptying was measured indirectly (paracetamol absorption).
Wilding et al. 2021 ²⁵	Humans	1,961	Phase III trial (controlled, blinded)	Industry	Originating group	In 1,961 adults with obesity or overweight without diabetes, mean body weight fell 14.9% with weekly semaglutide versus 2.4% with placebo over 68 weeks, alongside lifestyle support.	Weight is a surrogate; 68 weeks; gastrointestinal effects may have partly unblinded participants; manufacturer-run.
Rubino et al. 2021 ³⁴	Humans	803	Phase III trial (controlled, blinded)	Industry	Originating group	After a 20-week run-in on semaglutide, 803 adults were randomised: those who continued lost a further 7.9% of body weight over 48 weeks, while those switched to placebo regained 6.9%.	Only people who tolerated the drug in the run-in were randomised; manufacturer-run.
Wilding et al. 2022 ²⁸	Humans	327	Randomised controlled trial (controlled)	Industry	Originating group	Of 327 STEP 1 participants followed for a year after stopping, those who had taken semaglutide regained about two-thirds of the weight they had lost (net loss 5.6% at week 120); most cardiometabolic improvements moved back towards baseline.	Exploratory analysis of a subset from selected countries and sites; lifestyle support also stopped.
Bezin et al. 2023 ⁴²	Humans	47,746	Observational study (controlled)	Government	Independent group	In French national insurance data (2,562 thyroid cancer cases, 45,184 matched controls), one to three years of GLP-1 receptor agonist use was associated with more thyroid cancer (adjusted HR 1.58) and more medullary thyroid cancer (HR 1.78).	Observational; mostly older GLP-1 drugs, not semaglutide specifically; people on these drugs may have more thyroid checks, which finds more small cancers.
Lincoff et al. 2023 ²⁶	Humans	17,604	Phase III trial (controlled, blinded)	Industry	Originating group	In 17,604 adults with cardiovascular disease and overweight or obesity but no diabetes, followed for a mean of 39.8 months, heart attack, stroke or cardiovascular death occurred in 6.5% with semaglutide and 8.0% with placebo (HR 0.80).	Only people with existing cardiovascular disease; 16.6% stopped the drug because of adverse events (8.2% on placebo); manufacturer-run.
Perkovic et al. 2024 ²⁷	Humans	3,533	Phase III trial (controlled, blinded)	Industry	Originating group	In 3,533 people with type 2 diabetes and chronic kidney disease, followed for a median 3.4 years, major kidney events or kidney/cardiovascular death were 24% less frequent with semaglutide (HR 0.76); cardiovascular death HR 0.71.	Stopped early at a prespecified interim analysis, which tends to overstate effect size; people with type 2 diabetes only.
Hathaway et al. 2024 ⁴¹	Humans	1,689	Observational study (controlled)	Academic	Independent group	In 1,689 propensity-matched patients seen at one neuro-ophthalmology service, those prescribed semaglutide had a higher rate of NAION than patients on other medicines (HR 4.28 in type 2 diabetes, 7.64 in overweight or obesity).	Retrospective, single centre, referral population that over-represents eye disease; few events and wide confidence intervals; cannot show cause.
Pasternak et al. 2024 ⁴³	Humans	437,077	Observational study (controlled)	Academic	Independent group	In Danish, Norwegian and Swedish registers, starting a GLP-1 receptor agonist (145,410 people) was not associated with more thyroid cancer than starting a DPP-4 inhibitor (291,667 people) over a mean 3.9 years (HR 0.93, 95% CI 0.66–1.31).	Observational; several GLP-1 drugs pooled; mean follow-up under four years is short for cancer; too few medullary cancers to be precise (HR 1.19, 95% CI 0.37–3.86).
McGuire et al. 2025 ³²	Humans	9,650	Phase III trial (controlled, blinded)	Industry	Originating group	In 9,650 people with type 2 diabetes and atherosclerotic disease and/or chronic kidney disease, followed for a mean 47.5 months, major cardiovascular events occurred in 12.0% with oral semaglutide and 13.8% with placebo (HR 0.86).	The confirmatory secondary outcomes, including a kidney composite, did not differ significantly; manufacturer-run.
Cummings et al. 2026 ⁴⁰	Humans	3,808	Phase III trial (controlled, blinded)	Industry	Originating group	In 3,808 people with early Alzheimer's disease, oral semaglutide did not slow decline on the CDR-SB scale at 104 weeks compared with placebo, in either of two trials.	A clearly negative result in one indication; it does not test prevention, and it was oral rather than injected semaglutide.

Large trials do not make every claim about semaglutide true. Below is what each key study tested, in whom, and what it could not show. (The 1987 physiology study in the table explains the mechanism; it is not evidence that the medicine works.¹⁶)

In detail Diabetes, the heart and the kidneys

Type 2 diabetes and the heart

Semaglutide lowers HbA1c in type 2 diabetes (Evidence level: Established in large trials and authorised use) (in PIONEER 1, a double-blind, placebo-controlled phase 3 trial in 703 adults, at all three tablet strengths over 26 weeks).²⁹ But lower glucose does not by itself mean fewer heart attacks. SUSTAIN-6 randomised 3,297 people with type 2 diabetes at high cardiovascular risk to weekly semaglutide (0.5 mg or 1.0 mg) or placebo for 104 weeks: cardiovascular death, non-fatal heart attack or non-fatal stroke occurred in 6.6% versus 8.9% (HR 0.74, 95% CI 0.58–0.95).³⁰ It was designed to rule out harm, so the favourable result was encouraging rather than conclusive. PIONEER 6 did the same check for the tablet in 3,183 people over a median 15.9 months (3.8% versus 4.8%; HR 0.79, 95% CI 0.57–1.11): no large excess risk, but no proof of benefit.³¹

SOUL then tested benefit directly in 9,650 people with type 2 diabetes and atherosclerotic disease, chronic kidney disease or both, over a mean 47.5 months: major cardiovascular events occurred in 12.0% with oral semaglutide and 13.8% with placebo (HR 0.86, 95% CI 0.77–0.96) (Evidence level: Shown in controlled human trials); the confirmatory secondary outcomes, including a kidney composite, did not differ significantly.³²

Kidneys

FLOW randomised 3,533 people with type 2 diabetes and chronic kidney disease to weekly semaglutide or placebo (median follow-up 3.4 years). Kidney failure, a fall in kidney function of at least half, or kidney or cardiovascular death was 24% less frequent with semaglutide (HR 0.76, 95% CI 0.66–0.88) (Evidence level: Shown in controlled human trials).²⁷ It stopped early at a prespecified interim analysis. Trials stopped early for benefit tend to overstate the effect, although large overestimates are mainly seen in trials with fewer than 500 events; FLOW had 741.^33,27

Heart outcomes without diabetes

SELECT randomised 17,604 adults with cardiovascular disease and overweight or obesity, but no diabetes, for a mean 39.8 months. Cardiovascular death, non-fatal heart attack or non-fatal stroke occurred in 6.5% with semaglutide and 8.0% with placebo (HR 0.80, 95% CI 0.72–0.90) (Evidence level: Shown in controlled human trials); 16.6% stopped because of adverse events, against 8.2% on placebo.²⁶ It does not show that semaglutide prevents a first heart attack in people without heart or vessel disease.

In detail Weight management, and what happens after stopping

STEP 1 randomised 1,961 adults with obesity, or overweight with a weight-related condition, and no diabetes, to weekly semaglutide (2.4 mg) or placebo for 68 weeks, with lifestyle support. Mean weight fell by 14.9% versus 2.4% (Evidence level: Established in large trials and authorised use); half of the semaglutide group lost 15% or more, while about one in seven lost less than 5%.²⁵

Much of the effect is lost when treatment stops (Evidence level: Shown in controlled human trials). In STEP 4, a double-blind phase 3 trial, 803 people who had reached the target dose during a 20-week run-in on semaglutide (average loss 10.6%) were randomised to continue (a further 7.9% lost over 48 weeks) or switch to placebo (6.9% regained).³⁴ In the STEP 1 extension, of 327 people followed for a year after stopping, those who had taken semaglutide regained about two-thirds of the weight they had lost (a net loss of 5.6% remained), and most measures of blood pressure, lipids and glucose moved back towards baseline.²⁸

The daily tablet for weight management was tested in OASIS 4, a manufacturer-funded, double-blind, placebo-controlled trial in 307 adults without diabetes: mean weight change at 64 weeks was −13.6% versus −2.2%, with gastrointestinal adverse events in 74.0% versus 42.2%.³⁵ The EMA cites the same trial, as phase 3, for its tablet recommendation.³⁶

In detail Newer uses, and a negative result

In the US, Wegovy has accelerated approval (2025) for the liver disease MASH with moderate to advanced scarring but no cirrhosis; continued approval depends on confirmatory trial results.³⁷ ESSENCE, a manufacturer-funded, double-blind, placebo-controlled phase 3 trial, reported a planned interim analysis of its first 800 participants at 72 weeks: on biopsy, steatohepatitis resolved without worsening fibrosis in 62.9% versus 34.3%, and fibrosis improved without worsening steatohepatitis in 36.8% versus 22.4%. The trial continues for clinical liver outcomes.³⁸ In people who already had MASH cirrhosis, a smaller phase 2 trial (71 adults, 48 weeks) found no significant improvement in fibrosis or steatohepatitis.³⁹ The indication is not in the EU label.³

Health-record studies had suggested less dementia on GLP-1 medicines, but in the double-blind, placebo-controlled phase 3 evoke and evoke+ trials (3,808 people with early Alzheimer’s disease) oral semaglutide did not slow clinical decline over 104 weeks (Evidence level: Shown in controlled human trials).⁴⁰

In detail Who paid for the evidence

Every pivotal trial here was funded by the manufacturer, with many company authors. That is normal for medicines and does not make the results false, but the questions asked were mostly the manufacturer’s. A crude PubMed count on 20 October 2026 found 118 randomised-trial records on semaglutide (of 311) with no Novo Nordisk-affiliated author; some of these may still be company-funded. The main recent safety questions, NAION, thyroid cancer and suicidal thoughts, were tested by independent academic groups and regulators.^41,42,43,44 The weight effect has also been seen without company authors: in a Mayo Clinic cohort study, the 102 adults followed for six months lost 10.9% of their weight on average, similar to the trials. It was an observational study with no comparison group.⁴⁵

What is genuinely unknown

What is still not known?

What many years of use do, how to stop well, and how large some rare risks are.

The longest trials followed people for about four years on average. What longer use does is not known. Years of use covered by the evidence, counted from the start of treatment.

Longest outcome trial (SOUL)

about 4 years on average (47.5 months)
Weight-loss evidence checked in the Netherlands (2024)

no data beyond 2 years
Longer use

Not known: not covered by the trials

Sources McGuire et al. (2025); Zorginstituut Nederland (2024)^32,46

In detail All eight open questions, with their sources

Use beyond a few years. The longest outcome trials averaged about four years; in June 2024 Zorginstituut Nederland wrote that, in the weight-management evidence it assessed, there were no data on use beyond two years.^32,46
How to stop. Weight returns after stopping, and no trial has tested a way of tapering off while keeping the benefit.^46,28
NAION. The size of the risk outside type 2 diabetes, who is most at risk, and whether it depends on dose or speed of weight loss.⁴⁷
Thyroid cancer. Registry studies disagree and follow-up is short; the rodent finding has neither been shown to apply to people nor fully ruled out.^42,43
Muscle and function. How much lean mass lost is muscle, and whether it matters for strength and falls in older people.⁴⁸
Pregnancy. Animal studies showed harm to the embryo; human data are limited.³
The 7.2 mg Wegovy pen. More altered skin sensation than lower strengths; experience is still short.³
Who benefits most. Zorginstituut could not determine which patients with obesity gain the most health.⁴⁹

Regulatory status

Is it legal?

Yes, on prescription, in the EU, UK and US. Dutch basic insurance covers only diabetes use, with conditions.

Semaglutide has been an authorised medicine in the EU since 2018. Wegovy tablets came in 2026. Each bar runs from the EU authorisation to the day we checked.

Ozempic: weekly injection, type 2 diabetes

since 8 February 2018
Rybelsus: daily tablet, type 2 diabetes

since 3 April 2020
Wegovy: weekly injection, weight management

since 6 January 2022
Wegovy: daily tablet, weight management

since 14 July 2026

Sources Ozempic (semaglutide); Rybelsus (semaglutide); Wegovy (semaglutide); Wegovy^1,2,3,10 Checked 20 October 2026

In detail Status in each country and in sport

Regulatory status by jurisdiction
Jurisdiction	Status	Note	Checked
European Union	Authorised Since 8 February 2018	Authorised (centralised): Ozempic 8 Feb 2018, Rybelsus 3 Apr 2020, Wegovy injection 6 Jan 2022, Wegovy tablets 14 Jul 2026. Prescription only. ^1,2,3,10	20 October 2026
Netherlands	Authorised Since 8 February 2018	Authorised via the EU. Ozempic and Rybelsus reimbursed only for type 2 diabetes under Bijlage 2 conditions; Wegovy not reimbursed, reassessment under way. Ozempic shortage resolved 2 Dec 2024. ^1,53,55,57	20 October 2026
Germany	Authorised Since 8 February 2018	Authorised via the EU. Supply-shortage recommendation for Ozempic lifted on 18 Mar 2026. Falsified Ozempic pens containing insulin found in 2023. ^1,59	20 October 2026
Belgium	Authorised Since 8 February 2018	Authorised via the EU; prescription only. ¹	20 October 2026
United Kingdom	Authorised	Licensed by the MHRA (Ozempic, Rybelsus, Wegovy); prescription only. MHRA: powder-in-vial products are not authorised. ⁴	20 October 2026
United States	Authorised Since 5 December 2017	FDA-approved: Ozempic 5 Dec 2017, Rybelsus 20 Sep 2019, Wegovy 4 Jun 2021, Wegovy tablets 22 Dec 2025. Shortage declared resolved 21 Feb 2025. ^60,61,62,63	20 October 2026
Sport (WADA)	Not on the Prohibited List	Not on the 2026 Prohibited List. On the WADA Monitoring Program since 2024 (in and out of competition). ^50,51	20 October 2026

Statuses were checked on 20 October 2026.

Sport (WADA)

Semaglutide is not on the 2026 Prohibited List, and the S0 class for non-approved substances does not apply to an approved medicine.⁵⁰ It has been on the WADA Monitoring Program since 2024: laboratories look for it to detect misuse patterns, but it is not banned.⁵¹

In detail The European Union and the Netherlands

European Union

All three are authorised through the centralised procedure, valid in every member state; Wegovy tablets and a higher-strength pen were added in July 2026.^1,2,3,10 The EMA safety committee (PRAC) concluded that the evidence does not support a causal link with suicidal thoughts (April 2024);⁴⁴ that labels should warn about residual stomach content before anaesthesia, although no causal link with aspiration was established (July 2024);⁵² and that NAION is a very rare side effect (June 2025).⁴⁷

Netherlands

The EU authorisations apply directly; semaglutide is prescription-only. Reimbursement is uneven:^53,54

Ozempic and Rybelsus are reimbursed for type 2 diabetes only, under the conditions of Bijlage 2 of the Regeling zorgverzekering (for example a BMI of at least 30 when other medicines are not enough, or a very high cardiovascular risk).
Wegovy is not reimbursed. In July 2024 Zorginstituut Nederland called it effective for weight loss but advised against reimbursement, citing unclear health gain, long-term effect and way of stopping, and costs of up to €1.3 billion a year.⁴⁹ A reassessment, first for people with a BMI of 30 or more with related disease or a BMI of 35 or more, had its first scientific discussion on 5 October 2026; consultation is expected in early November 2026.^55,56

This gap has real costs, and the reasons for it are also real. An authorised weight-management medicine has existed since 2022, with outcome-trial evidence in people with heart disease since 2023,^3,26 but people who cannot pay do not get it, while the CBG notes that these medicines are increasingly used as slimming aids without a prescription.⁵ Whether non-reimbursement pushes people towards online products has not been measured. Equally, the Zorginstituut’s concerns about long-term evidence, stopping, and a budget impact that could displace other care are legitimate.

In March 2023 the CBG warned of a long Ozempic shortage and against slimming use without a doctor; it later noted that it was unclear whether off-label use had caused the shortage, which ended on 2 December 2024.⁵⁷ In June 2024, reporting EMA recommendations, it wrote that slimming use by people without obesity had made shortages much worse, and that GLP-1 medicines sold online may be falsified.⁵⁸

In detail Germany, Belgium, the United Kingdom and the United States

Germany

Authorised through the EU procedure.¹ The BfArM’s shortage advisory board lifted its Ozempic recommendation on 18 March 2026.⁵⁹ Falsified German-labelled Ozempic pens found in 2023 contained insulin, not semaglutide.⁶

Belgium

Authorised through the EU procedure; prescription-only.¹ Additional Belgian prescribing or reimbursement rules are not covered, because we could not verify them on the regulator’s website on 20 October 2026.

United Kingdom

The MHRA lists Ozempic, Rybelsus and Wegovy as licensed, prescription-only medicines; GLP-1 products supplied as powder in vials are not authorised.⁴ In 2023 it reported seizing 369 potentially fake Ozempic pens, and hospital admissions suggesting that some fakes contained insulin.⁷

United States

The FDA approved Ozempic on 5 December 2017, Rybelsus on 20 September 2019, Wegovy injection on 4 June 2021 and Wegovy tablets on 22 December 2025, later adding cardiovascular risk reduction for Wegovy (March 2024) and a kidney indication for Ozempic (January 2025).^60,61,62,63

The US and EU labels differ. US labels carry a boxed warning on rodent thyroid C-cell tumours and contraindicate use with a personal or family history of medullary thyroid carcinoma or MEN 2; EU labels list only hypersensitivity.^11,3 The US Wegovy label dropped its suicidal-behaviour warning in early 2026, and the US Ozempic and Wegovy labels we checked (revised May and June 2026) do not list NAION.^37,11

From 2022 semaglutide injections were on the FDA shortage list, which let pharmacies compound copies. The FDA declared the shortage resolved on 21 February 2025; the grace period ended for pharmacies after a court ruling on 24 April 2025 and for outsourcing facilities on 22 May 2025.⁶⁴ In April 2026 the FDA proposed not to put semaglutide on the list of bulk substances that outsourcing facilities may compound from; the comment period was extended to 30 July 2026, and no final decision had been published by 20 October 2026.^65,66 By 31 May 2026 the FDA had 990 adverse-event reports for compounded semaglutide, likely an undercount.⁹

Risk profile

What are the risks?

Many people feel sick at first. Gallstones, an inflamed pancreas and a rare eye condition are rarer.

Stomach and gut problems were common, mostly while the dose was being raised. People in 100 who had each problem in the Wegovy weight trials (STEP 1–4, 68 weeks).

Feeling sick (nausea)

44 in 100 Semaglutide

16 in 100 Placebo
Diarrhoea

30 in 100 Semaglutide

16 in 100 Placebo
Vomiting

25 in 100 Semaglutide

6 in 100 Placebo
Constipation

24 in 100 Semaglutide

11 in 100 Placebo

Each square is one person in 100. Source Wegovy (semaglutide)³ Evidence Human trials

Unless stated otherwise, risks and frequencies come from the EU product information and the trials named.

In detail Stomach and gut: the exact numbers

In the Wegovy weight trials (STEP 1–4, 68 weeks), nausea occurred in 43.9% with semaglutide versus 16.1% with placebo, diarrhoea in 29.7% versus 15.9%, vomiting in 24.5% versus 6.3% and constipation in 24.2% versus 11.1%. Most episodes were mild to moderate and came while the dose was being raised; 4.3% stopped treatment permanently because of them. Dehydration from vomiting or diarrhoea has rarely worsened kidney function, and intestinal obstruction has been reported after authorisation.³

In detail Gallbladder and pancreas

Gallstones were reported in 1.6% versus 1.1%, and gallbladder inflammation in 0.6% versus 0.3%.³ A meta-analysis of 76 randomised trials of GLP-1 medicines (103,371 participants) found more gallbladder and bile-duct disease (relative risk 1.37), more so in weight-loss trials, at higher doses and with longer use (Evidence level: Shown in controlled human trials).⁶⁷ Adjudicated acute pancreatitis occurred in 0.2% versus less than 0.1% in the weight trials, and 0.2% versus 0.3% in SELECT; semaglutide should be stopped if pancreatitis is suspected and not restarted if it is confirmed.³

In detail Eyes: diabetic retinopathy and NAION

Eyes: diabetic retinopathy

In SUSTAIN-6, diabetic retinopathy complications (bleeding in the eye, blindness, or the need for laser or eye injections) occurred in 3.0% versus 1.8% (HR 1.76), mainly in insulin-treated people with existing retinopathy.^30,3 A manufacturer-funded post hoc analysis of SUSTAIN-6 suggested that most of the excess may be due to the size and speed of the fall in HbA1c in the first 16 weeks (Evidence level: Seen in humans in case reports or small uncontrolled studies), an “early worsening” also seen with insulin.⁶⁸ The label notes that other mechanisms cannot be excluded.³

Eyes: NAION

The PRAC classes NAION as very rare (up to 1 in 10,000 people): large epidemiological studies in type 2 diabetes suggest roughly a doubling of risk, about one extra case per 10,000 person-years (Evidence level: Seen in humans in case reports or small uncontrolled studies).⁴⁷ An earlier retrospective single-centre study of 1,689 matched patients found much higher hazard ratios (4.28 and 7.64), with few events and wide confidence intervals, in patients referred to a specialist eye service.⁴¹ Neither the PRAC announcement nor the EU label proposes a mechanism.^47,3

In detail Low blood sugar, with a short animation

Semaglutide’s own risk of hypoglycaemia is low because its insulin effect depends on glucose, but it is not zero: in STEP 2, a weight trial in people with type 2 diabetes, clinically significant low blood sugar occurred in 6.2% with semaglutide versus 2.5% with placebo, with and without a sulfonylurea. Insulin and sulfonylureas act regardless of glucose, so in combination blood sugar can fall too low; the label says this risk can be lowered by reducing the dose of those medicines.³

The animation shows how the combination pushes blood sugar too low, and what to do about it.

Animation · 25 seconds Semaglutide with insulin or a sulfonylurea: the risk of low blood sugar

1 Semaglutide alone lowers high blood sugar. Near normal, it works less, so sugar rarely gets too low.

2 Insulin lowers sugar too. So do tablets called sulfonylureas. They still work when sugar is normal or low.

3 Used together, they can push blood sugar too low. This is called hypoglycaemia.

4 So your prescriber may lower your dose of insulin or these tablets, as the label suggests.

5 Low sugar signs: sweating, shaking, hunger, confusion. Take sugar now. Can't swallow? Call an ambulance.

On its own, semaglutide rarely makes sugar too low. With insulin or these tablets, it can.

Your device asks for less motion, so this animation does not play. The picture shows the end result and the list explains every step.

Semaglutide alone lowers high blood sugar. Near normal, it works less, so sugar rarely gets too low.

Evidence: In humans
Insulin lowers sugar too. So do tablets called sulfonylureas. They still work when sugar is normal or low.

Evidence: In humans
Used together, they can push blood sugar too low. This is called hypoglycaemia.

Evidence: In humans
So your prescriber may lower your dose of insulin or these tablets, as the label suggests.

Evidence: In humans
Low sugar signs: sweating, shaking, hunger, confusion. Take sugar now. Can't swallow? Call an ambulance.

Evidence: In humans

In short: On its own, semaglutide rarely makes blood sugar too low. With insulin or a sulfonylurea tablet it can, so the prescriber may lower those doses. Know the signs and take sugar at once. If the person cannot swallow, call an ambulance.

Lines: solid = shown in people

Based on: Ozempic (semaglutide)¹; Sola et al. (2015)⁶⁹; American Diabetes Association Professional Practice Committee for Diabetes (2026)⁷⁰

In detail Thyroid tumours in rodents, and why they may not carry over

In two-year studies, semaglutide caused thyroid C-cell tumours in rats and mice at clinically relevant exposures.^3,11 Rodent C-cells carry GLP-1 receptors, and GLP-1 agonists stimulated calcitonin release and, over time, C-cell hyperplasia in rats and, less, in mice (Evidence level: Shown in animal studies). Human and monkey C-cells had low receptor levels, the agonists did not switch on adenylate cyclase or calcitonin release in primates, and 20 months of liraglutide caused no C-cell hyperplasia in monkeys (Evidence level: Shown in animal studies).⁷¹ The EU label rates human relevance as low but not excluded.³

Human data are mixed: a French case-control study linked one to three years of GLP-1 medicines with more thyroid cancer, including medullary cancer, while a larger Scandinavian cohort found no clear increase over a mean 3.9 years but could not rule out a modest one. Both analysed GLP-1 medicines as a class rather than semaglutide alone; in the Scandinavian study, semaglutide made up about a third of use.^42,43 More thyroid check-ups in people on these medicines would find more small cancers and could inflate an observed risk (Evidence level: Proposed, not demonstrated in any experiment). The US contraindication covers a personal or family history of medullary thyroid carcinoma, or MEN 2, where the baseline risk is already high.¹¹

In detail Anaesthesia, muscle, weight regain, mood and pregnancy

Anaesthesia, muscle and weight regain

Slower stomach emptying means food may remain in the stomach during general anaesthesia or deep sedation, and could be breathed into the lungs; cases have been reported, so tell the doctor about semaglutide before a procedure.^52,3

In trials of GLP-1-based medicines, lean mass has made up from about 15% to 40–60% of the weight lost (Evidence level: Seen in humans in case reports or small uncontrolled studies). Lean mass also includes organs, bone and water, and MRI studies suggest the muscle change may fit the weight lost, but older or frail people may lose function; the source is a narrative review and the question is open.⁴⁸

In the STEP 1 extension, about two-thirds of the lost weight returned within a year of stopping, and most gains in blood pressure, lipids and glucose faded; the STEP 1 investigators see this as confirming that obesity is chronic.^28,34

Mood, pregnancy and other effects

The PRAC concluded that the available evidence does not support a causal link with suicidal thoughts; if your mood changes on any medicine, tell your doctor.⁴⁴

In rats semaglutide harmed embryos, partly through a yolk-sac mechanism thought not to apply to humans; rabbits and monkeys had more pregnancy loss with marked maternal weight loss. The label says not to use it in pregnancy or while breastfeeding, and to stop at least two months before a planned pregnancy.³ Weight loss can improve fertility and so raise the chance of an unplanned pregnancy.⁵³

The label also lists a rise in heart rate (on average about 3 beats per minute), hair loss (2.5% versus 1.0%), headache, dizziness, tiredness, rare allergic reactions including anaphylaxis and angioedema, and, mainly at 7.2 mg, altered skin sensation (21.6% versus 0.3% in STEP UP).³

Using it safely and legally

How do I use it safely?

The pharmacy medicine has the fewest unknowns. Check any other product first, and know when to get help.

The authorised medicine is a pen or tablet from a pharmacy, on prescription. A regulator assessed what is in it, the pen or tablet fixes the amount, and the maker releases each batch.^1,2,3 This section gives no doses: your prescriber decides the dose. Tell your doctor about other medicines you use.

The checks below are for any other product, such as an online “research” vial or a pen of unknown origin.

If your product did not come from a pharmacy: check before you use it

These checks can show that something is wrong. None of them can show that a product is good or free of germs.^72,73,74

Tick each box when you have checked it.

The seal and the vial are whole

A broken cap or seal, or a cracked vial, can let germs in. Then do not use it.^75,76,77
The label shows the name, amount, batch number and expiry date

In the EU, a medicine must show all four, even on a small vial. If one is missing, or the date has passed, that is a warning sign. Take a photo of the label.^78,75
For Semaglutide

A pen can be fake too. Compare it with the picture in the package leaflet. Does it look different? Then do not use it. Some fake pens held insulin, which can make blood sugar fall too low.^95,6,7
It looks right

A liquid, or a powder after mixing, should be clear and colourless, with no bits. Is it cloudy, has it changed colour, or do you see bits? Then do not use it.^79,3
A lab report proves little if:
- its batch number is not the one on your vial;
- it does not name the lab, or has no date or signature;
- it shows only purity (HPLC), with no test of what it is, such as mass spectrometry;
- it has no test for germs (sterility) or for toxins from germs (endotoxin).
Even a full report covers only one sample. A report from the seller comes from someone who gains if it looks good. It cannot show that your vial is clean.^{80,81,82,83,84}

What a certificate of analysis shows, and what it does not
It was kept as the label says

Heat, freezing and sunlight can damage a peptide. Did it arrive warm, or was it frozen? Then do not use it. Often nobody can tell you how it was kept on the way. If you cannot know, you cannot rule out damage. When in doubt, throw it out.^3,9,85,77

When to throw a vial away
Clean steps, and a new sterile needle and syringe every time

Wash your hands and wipe the rubber top with alcohol. Never share a needle, a syringe or a vial.^77,86,9

Sterile technique, step by step
Keep the vial, its label and any papers

Keep them, even when the vial is empty, until you know you feel well. If you need a doctor, bring them. A lab can test what was inside.^87,88

If something goes wrong
Tell a doctor, and agree which checks fit you

A doctor can help you choose blood tests that fit what you use. In the Netherlands, your doctor must keep what you say private.^89,90,91

Which checks matter, and why Talking to your doctor
Know the warning signs before you start

Spreading redness, fever, a swollen face or hard breathing need help fast. If it is severe, call your local emergency number.^92,93,94

All warning signs, and how fast to act

When to stop and get help

Stop and seek care: Get medical help now

Severe, constant pain in the upper belly, often into the back, with or without vomiting: possible pancreatitis. Stop semaglutide and get urgent care.
Sudden loss of vision or rapidly worsening eyesight, often in one eye: possible NAION. Contact a doctor without delay.
Shaking, sweating, confusion or drowsiness after injecting a product from outside a pharmacy: possibly insulin in a fake. Take something sugary if you can swallow safely; call your local emergency number if symptoms are severe or the person becomes drowsy or confused.
Swelling of the face, lips or throat, or difficulty breathing: possible allergic reaction. Call your local emergency number.
Vomiting so much you cannot keep fluids down, or passing very little urine: risk of dehydration and kidney injury. Get same-day care.

Sources 3, 47, 7

Stop-now warning signs

Call your local emergency number now

Confusion or slurred speech, very fast breathing, or pale, blue or blotchy skin, often with fever or shivering These can be signs of sepsis: the body's reaction to an infection has started to damage its own organs.
Fainting and not waking up within a minute, or fainting with chest pain, a racing heart or a fit This can be a dangerous heart rhythm or a severe allergic reaction.
Pain at the injection spot that is much worse than it looks, or dark, purple or grey patches or blisters there This can be a rare, fast-spreading infection of the deep layers under the skin (necrotising fasciitis).
Swelling of the lips, tongue or throat, trouble breathing or swallowing, wheezing, a hoarse voice, or feeling faint, soon after an injection This can be a severe allergic reaction (anaphylaxis), which is life-threatening and gets worse very quickly.
Pain, pressure or tightness in the chest, or pain that spreads to the arm, neck, jaw or back This can be a heart attack, which needs treatment in hospital straight away.
Sudden, severe shortness of breath: gasping, or not able to finish a sentence This can be a serious problem with the heart, the lungs or an allergic reaction.
A racing, pounding or irregular heartbeat that does not settle, or that comes with chest pain, breathlessness or fainting This can be a dangerous heart rhythm.
A sudden, severe headache with blurred vision, chest pain, confusion or vomiting Blood pressure may be dangerously high, which can damage the brain, heart, kidneys and eyes.
An erection that lasts more than 3 hours, or a painful erection that will not go down Blood trapped in the penis can damage it for good if it is not treated quickly.
Shaking, sweating or sudden hunger that turns into confusion or drowsiness Very low blood sugar can cause a fit or loss of consciousness; take something sugary if you can still swallow safely.
Severe, constant pain in the upper belly that spreads to the back, often with vomiting This can be an inflamed pancreas (pancreatitis), a known risk of GLP-1 medicines such as semaglutide and tirzepatide.
Sudden weakness or numbness on one side, a drooping face, or slurred or confused speech These are signs of a stroke, which needs treatment in hospital straight away, even if the signs pass.
A headache that starts suddenly and is extremely painful, or a headache with a stiff neck, confusion or a fit This can be a stroke or another emergency in the brain.
Sudden loss of sight in one or both eyes This can be a stroke or damage to the nerve of the eye, and sight can be lost for good.
A fit (seizure): jerking movements, or suddenly not responding A fit can be caused by very low blood sugar or a problem in the brain, and needs checks straight away.

Get medical help today

Fever, shivering or feeling very ill in the days after an injection Germs from the needle, the skin or the product may have reached your blood. If you also have a fast heartbeat or fast breathing, call your local emergency number.
Redness, heat, swelling or pain around the injection spot that keeps growing or getting worse This can be a skin infection (cellulitis), which needs antibiotics before it spreads.
Red lines that run from the injection spot towards the armpit or groin The infection may be spreading along the lymph vessels, and from there into the blood. If you also have a fever with a fast heartbeat or fast breathing, call your local emergency number.
A painful, warm lump that fills with pus This is probably an abscess: it often needs draining by a doctor, so do not squeeze it.
You were pricked by a needle that someone else had used Blood on a used needle can pass on HIV and hepatitis B or C, and preventive treatment works best within hours.
Vomiting so often that you cannot keep fluids down, or passing very little urine Losing too much fluid can damage the kidneys.
Yellow skin, or yellow whites of the eyes This can be a sign of a liver problem, gallstones or an inflamed pancreas.
Dark, red or cola-coloured urine together with muscle pain, tenderness or weakness Damaged muscle can release a protein that harms the kidneys (rhabdomyolysis).

Stop and contact a doctor

You fainted, but woke up quickly and now feel well Fainting is often harmless, but a doctor should check the cause.
A new mole, or a mole that changes size, shape or colour, itches or bleeds A changing mole can be skin cancer, and tanning peptides such as melanotan II have been linked to new and changing moles in case reports.
A lump at an injection spot that does not go away, or keeps growing A doctor should check whether it is an abscess, a reaction to the product or something else.
An itchy, raised rash, or puffy eyes or lips, while breathing stays normal Your body may be reacting to the product, and using it again can bring the reaction back.
Palpitations that keep coming back, even if they pass and you then feel well A doctor can check whether your heart rhythm is normal.

In detail The legal route, and why an online vial is different

For an authorised medicine, the legal route has the fewest unknowns.

The legal route in the Netherlands

Semaglutide needs a prescription from a doctor, usually your GP (huisarts) or a specialist, and comes from a pharmacy. Ozempic or Rybelsus may be reimbursed for diabetes under conditions; Wegovy is authorised for weight management but, as of 20 October 2026, basic health insurance does not pay for it.^53,55 Dutch prescribing advice adds obesity medicines to a combined lifestyle programme (GLI), not instead of it.⁵³ A prescription brings a check that the medicine suits you, interaction checks and follow-up by a doctor and pharmacist;⁵ see talking to your doctor.

Why an online “research” vial is a different product

The FDA has warned companies selling semaglutide falsely labelled “for research purposes” or “not for human consumption” to consumers, and calls such products of unknown quality. It also warns that some compounded products use salt forms (semaglutide sodium or acetate), which are different active ingredients from the one in the authorised medicines.⁹ The MHRA states that powder-in-vial GLP-1 products are not authorised.⁴ The CBG’s summary: you do not know what is in it, how to use it, or what it will do to your health.⁵ See product risk.

Vials also bring dosing errors that pens prevent. The FDA has reports of people taking five to 20 times the intended amount from multi-dose vials of compounded semaglutide, often from confusing milligrams, millilitres and syringe “units”. Some needed hospital care; with a one-week half-life, overdose may need prolonged observation and treatment.⁸ For multi-dose vials of compounded GLP-1 medicines, the FDA advises a new sterile needle and syringe every time, discarding a vial 28 days after first use because contamination risk rises after that, and not using a product that arrived warm.⁹ See sterile technique.

In detail Fake pens, and how to check yours

Falsified Ozempic pens have been found in the EU, the UK and elsewhere since 2023; some contained insulin, which can cause dangerously low blood sugar.^95,6,7,96

Pens and tablets are prescription-only. The EU and Dutch regulators advise getting them only through a doctor and a pharmacy.
Compare your pen with the picture and description in the package leaflet.
Do not use a pen you suspect is fake, for example one that looks different from the leaflet; ask a pharmacist.
Report side effects to Lareb.

Sources 4, 95, 97, 98

If a pen did not come from a pharmacy, the checks at the top of this section apply to it too.

In detail Who should not use it, interactions, and useful checks

Who should not use it, and interactions

Pregnancy, trying to conceive, breastfeeding: animal harm to the embryo; stop at least two months before a planned pregnancy.³
Personal or family history of medullary thyroid carcinoma, or MEN 2: contraindicated in the US because of the rodent finding; not a formal EU contraindication, so discuss it.^11,3
Previous pancreatitis: use with caution, because GLP-1 medicines are linked to acute pancreatitis. Severe gastroparesis: not recommended, because semaglutide slows the stomach further. Uncontrolled or unstable diabetic retinopathy: not recommended, because there is no experience in this group and a fast fall in glucose can temporarily worsen retinopathy. Type 1 diabetes: not studied; semaglutide never replaces insulin.³
Insulin or sulfonylureas (such as gliclazide): higher risk of low blood sugar. Other GLP-1 medicines: do not combine.³
Tablets that need fast or precise absorption: slower stomach emptying can change absorption; with semaglutide tablets levothyroxine exposure rose by 33%.^3,2
Warfarin or other coumarins, such as acenocoumarol: cases of lower INR have been reported with acenocoumarol; the label advises frequent INR checks when starting.³

Checks that make sense, and why

Eyes, if you have diabetic retinopathy: a fast fall in glucose can temporarily worsen it, and the label asks for close monitoring.^68,3
Blood glucose, if you also use insulin or a sulfonylurea; INR on coumarins; thyroid tests on levothyroxine (see above).
Kidney function after prolonged vomiting or diarrhoea, because dehydration can harm the kidneys.³

Sources

Every claim on this page links to one of these sources. Scholarly sources link to their DOI; regulatory sources to the regulator's own page.

In detail All 98 sources, numbered as in the text

European Medicines Agency (2026). Ozempic (semaglutide): EPAR — overview and product information. Official product information ema.europa.eu (opens an external site) — accessed 20 October 2026 ↩
European Medicines Agency (2026). Rybelsus (semaglutide): EPAR — overview and product information. Official product information ema.europa.eu (opens an external site) — accessed 20 October 2026 ↩
European Medicines Agency (2026). Wegovy (semaglutide): EPAR — overview and product information. Official product information ema.europa.eu (opens an external site) — accessed 20 October 2026 ↩
Medicines and Healthcare products Regulatory Agency (2026). GLP-1 medicines for weight loss and diabetes: what you need to know. GOV.UK. Regulator gov.uk (opens an external site) — accessed 20 October 2026 ↩
College ter Beoordeling van Geneesmiddelen (CBG-MEB) (2026). Standpunt: Gebruik diabetes- en afslankmedicijnen alleen zoals ze bedoeld zijn. Regulator cbg-meb.nl (opens an external site) — accessed 20 October 2026 ↩
Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM) (2024). Fälschung des Arzneimittels Ozempic® (updates 11.10.2023 – 15.02.2024). Regulator bfarm.de (opens an external site) — accessed 20 October 2026 ↩
Medicines and Healthcare products Regulatory Agency (2023). MHRA warns of unsafe fake weight loss pens. GOV.UK. Regulator gov.uk (opens an external site) — accessed 20 October 2026 ↩
U.S. Food and Drug Administration (2024). FDA alerts health care providers, compounders and patients of dosing errors associated with compounded injectable semaglutide products. Regulator fda.gov (opens an external site) — accessed 20 October 2026 ↩
U.S. Food and Drug Administration (2026). FDA's concerns with unapproved GLP-1 drugs used for weight loss. Regulator fda.gov (opens an external site) — accessed 20 October 2026 ↩
European Medicines Agency (2026). Wegovy: EPAR — procedural steps taken and scientific information after authorisation. Regulator ema.europa.eu (opens an external site) — accessed 20 October 2026 ↩
U.S. Food and Drug Administration / Novo Nordisk (2026). OZEMPIC (semaglutide) injection — prescribing information (revised 05/2026). Official product information accessdata.fda.gov (opens an external site) — accessed 20 October 2026 ↩
Lau J, Bloch P, Schäffer L, Pettersson I, Spetzler J, Kofoed J, et al. (2015). Discovery of the once-weekly glucagon-like peptide-1 (GLP-1) analogue semaglutide. Journal of Medicinal Chemistry 58:7370-7380. Research article doi:10.1021/acs.jmedchem.5b00726 (opens an external site) ↩
National Center for Biotechnology Information (2026). PubChem Compound Summary for CID 56843331, Semaglutide. PubChem. Dataset pubchem.ncbi.nlm.nih.gov (opens an external site) — accessed 20 October 2026 ↩
Holst JJ, Orskov C, Nielsen OV, Schwartz TW (1987). Truncated glucagon-like peptide I, an insulin-releasing hormone from the distal gut. FEBS Letters 211:169-174. Research article doi:10.1016/0014-5793(87)81430-8 (opens an external site) ↩
Mojsov S, Weir GC, Habener JF (1987). Insulinotropin: glucagon-like peptide I (7-37) co-encoded in the glucagon gene is a potent stimulator of insulin release in the perfused rat pancreas. Journal of Clinical Investigation 79:616-619. Research article doi:10.1172/JCI112855 (opens an external site) ↩
Kreymann B, Williams G, Ghatei MA, Bloom SR (1987). Glucagon-like peptide-1 7-36: a physiological incretin in man. The Lancet 2:1300-1304. Research article doi:10.1016/s0140-6736(87)91194-9 (opens an external site) ↩
Nauck MA, Kleine N, Orskov C, Holst JJ, Willms B, Creutzfeldt W (1993). Normalization of fasting hyperglycaemia by exogenous glucagon-like peptide 1 (7-36 amide) in type 2 (non-insulin-dependent) diabetic patients. Diabetologia 36:741-744. Research article doi:10.1007/BF00401145 (opens an external site) ↩
Müller TD, Finan B, Bloom SR, D'Alessio D, Drucker DJ, Flatt PR, et al. (2019). Glucagon-like peptide 1 (GLP-1). Molecular Metabolism 30:72-130. Review doi:10.1016/j.molmet.2019.09.010 (opens an external site) ↩
Deacon CF, Nauck MA, Toft-Nielsen M, Pridal L, Willms B, Holst JJ (1995). Both subcutaneously and intravenously administered glucagon-like peptide I are rapidly degraded from the NH2-terminus in type II diabetic patients and in healthy subjects. Diabetes 44:1126-1131. Research article doi:10.2337/diab.44.9.1126 (opens an external site) ↩
Buckley ST, Bækdal TA, Vegge A, Maarbjerg SJ, Pyke C, Ahnfelt-Rønne J, et al. (2018). Transcellular stomach absorption of a derivatized glucagon-like peptide-1 receptor agonist. Science Translational Medicine 10:eaar7047. Research article doi:10.1126/scitranslmed.aar7047 (opens an external site) ↩
Kapitza C, Dahl K, Jacobsen JB, Axelsen MB, Flint A (2017). Effects of semaglutide on beta cell function and glycaemic control in participants with type 2 diabetes: a randomised, double-blind, placebo-controlled trial. Diabetologia 60:1390-1399. Clinical trial doi:10.1007/s00125-017-4289-0 (opens an external site) ↩
Gabery S, Salinas CG, Paulsen SJ, Ahnfelt-Rønne J, Alanentalo T, Baquero AF, et al. (2020). Semaglutide lowers body weight in rodents via distributed neural pathways. JCI Insight 5:e133429. Research article doi:10.1172/jci.insight.133429 (opens an external site) ↩
Friedrichsen M, Breitschaft A, Tadayon S, Wizert A, Skovgaard D (2021). The effect of semaglutide 2.4 mg once weekly on energy intake, appetite, control of eating, and gastric emptying in adults with obesity. Diabetes, Obesity and Metabolism 23:754-762. Clinical trial doi:10.1111/dom.14280 (opens an external site) ↩
EMBL-EBI (2026). ChEMBL compound CHEMBL2108724 (semaglutide): mechanism of action — glucagon-like peptide 1 receptor agonist. ChEMBL. Dataset ebi.ac.uk (opens an external site) — accessed 20 October 2026 ↩
Wilding JPH, Batterham RL, Calanna S, Davies M, Van Gaal LF, Lingvay I, et al. (2021). Once-weekly semaglutide in adults with overweight or obesity. New England Journal of Medicine 384:989-1002. Clinical trial doi:10.1056/NEJMoa2032183 (opens an external site) ↩
Lincoff AM, Brown-Frandsen K, Colhoun HM, Deanfield J, Emerson SS, Esbjerg S, et al. (2023). Semaglutide and cardiovascular outcomes in obesity without diabetes. New England Journal of Medicine 389:2221-2232. Clinical trial doi:10.1056/NEJMoa2307563 (opens an external site) ↩
Perkovic V, Tuttle KR, Rossing P, Mahaffey KW, Mann JFE, Bakris G, et al. (2024). Effects of semaglutide on chronic kidney disease in patients with type 2 diabetes. New England Journal of Medicine 391:109-121. Clinical trial doi:10.1056/NEJMoa2403347 (opens an external site) ↩
Wilding JPH, Batterham RL, Davies M, Van Gaal LF, Kandler K, Konakli K, et al. (2022). Weight regain and cardiometabolic effects after withdrawal of semaglutide: the STEP 1 trial extension. Diabetes, Obesity and Metabolism 24:1553-1564. Clinical trial doi:10.1111/dom.14725 (opens an external site) ↩
Aroda VR, Rosenstock J, Terauchi Y, Altuntas Y, Lalic NM, Morales Villegas EC, et al. (2019). PIONEER 1: randomized clinical trial of the efficacy and safety of oral semaglutide monotherapy in comparison with placebo in patients with type 2 diabetes. Diabetes Care 42:1724-1732. Clinical trial doi:10.2337/dc19-0749 (opens an external site) ↩
Marso SP, Bain SC, Consoli A, Eliaschewitz FG, Jódar E, Leiter LA, et al. (2016). Semaglutide and cardiovascular outcomes in patients with type 2 diabetes. New England Journal of Medicine 375:1834-1844. Clinical trial doi:10.1056/NEJMoa1607141 (opens an external site) ↩
Husain M, Birkenfeld AL, Donsmark M, Dungan K, Eliaschewitz FG, Franco DR, et al. (2019). Oral semaglutide and cardiovascular outcomes in patients with type 2 diabetes. New England Journal of Medicine 381:841-851. Clinical trial doi:10.1056/NEJMoa1901118 (opens an external site) ↩
McGuire DK, Marx N, Mulvagh SL, Deanfield JE, Inzucchi SE, Pop-Busui R, et al. (2025). Oral semaglutide and cardiovascular outcomes in high-risk type 2 diabetes. New England Journal of Medicine 392:2001-2012. Clinical trial doi:10.1056/NEJMoa2501006 (opens an external site) ↩
Bassler D, Briel M, Montori VM, Lane M, Glasziou P, Zhou Q, et al. (2010). Stopping randomized trials early for benefit and estimation of treatment effects: systematic review and meta-regression analysis. JAMA 303:1180-1187. Meta-analysis doi:10.1001/jama.2010.310 (opens an external site) ↩
Rubino D, Abrahamsson N, Davies M, Hesse D, Greenway FL, Jensen C, et al. (2021). Effect of continued weekly subcutaneous semaglutide vs placebo on weight loss maintenance in adults with overweight or obesity: the STEP 4 randomized clinical trial. JAMA 325:1414-1425. Clinical trial doi:10.1001/jama.2021.3224 (opens an external site) ↩
Wharton S, Lingvay I, Bogdanski P, Duque do Vale R, Jacob S, Karlsson T, et al. (2025). Oral semaglutide at a dose of 25 mg in adults with overweight or obesity. New England Journal of Medicine 393:1077-1087. Clinical trial doi:10.1056/NEJMoa2500969 (opens an external site) ↩
European Medicines Agency (2026). First oral GLP-1 treatment for weight management. Regulator ema.europa.eu (opens an external site) — accessed 20 October 2026 ↩
U.S. Food and Drug Administration / Novo Nordisk (2026). WEGOVY (semaglutide) injection and tablets — prescribing information (revised 06/2026). Official product information accessdata.fda.gov (opens an external site) — accessed 20 October 2026 ↩
Sanyal AJ, Newsome PN, Kliers I, Østergaard LH, Long MT, Kjær MS, et al. (2025). Phase 3 trial of semaglutide in metabolic dysfunction-associated steatohepatitis. New England Journal of Medicine 392:2089-2099. Clinical trial doi:10.1056/NEJMoa2413258 (opens an external site) ↩
Loomba R, Abdelmalek MF, Armstrong MJ, Jara M, Kjær MS, Krarup N, et al. (2023). Semaglutide 2·4 mg once weekly in patients with non-alcoholic steatohepatitis-related cirrhosis: a randomised, placebo-controlled phase 2 trial. The Lancet Gastroenterology & Hepatology 8:511-522. Clinical trial doi:10.1016/S2468-1253(23)00068-7 (opens an external site) ↩
Cummings JL, Atri A, Sano M, Zetterberg H, Scheltens P, Knop FK, et al. (2026). Efficacy and safety of oral semaglutide 14 mg (flexible dose) in early-stage symptomatic Alzheimer's disease (evoke and evoke+): two phase 3, randomised, placebo-controlled trials. The Lancet 407:2167-2179. Clinical trial doi:10.1016/S0140-6736(26)00459-9 (opens an external site) ↩
Hathaway JT, Shah MP, Hathaway DB, Zekavat SM, Krasniqi D, Gittinger JW, et al. (2024). Risk of nonarteritic anterior ischemic optic neuropathy in patients prescribed semaglutide. JAMA Ophthalmology 142:732-739. Research article doi:10.1001/jamaophthalmol.2024.2296 (opens an external site) ↩
Bezin J, Gouverneur A, Pénichon M, Mathieu C, Garrel R, Hillaire-Buys D, et al. (2023). GLP-1 receptor agonists and the risk of thyroid cancer. Diabetes Care 46:384-390. Research article doi:10.2337/dc22-1148 (opens an external site) ↩
Pasternak B, Wintzell V, Hviid A, Eliasson B, Gudbjörnsdottir S, Jonasson C, et al. (2024). Glucagon-like peptide 1 receptor agonist use and risk of thyroid cancer: Scandinavian cohort study. BMJ 385:e078225. Research article doi:10.1136/bmj-2023-078225 (opens an external site) ↩
European Medicines Agency (2024). Meeting highlights from the Pharmacovigilance Risk Assessment Committee (PRAC) 8-11 April 2024. Regulator ema.europa.eu (opens an external site) — accessed 20 October 2026 ↩
Ghusn W, De la Rosa A, Sacoto D, Cifuentes L, Campos A, Feris F, Hurtado MD, Acosta A (2022). Weight Loss Outcomes Associated With Semaglutide Treatment for Patients With Overweight or Obesity. JAMA Network Open 5:e2231982. Research article doi:10.1001/jamanetworkopen.2022.31982 (opens an external site) ↩
Zorginstituut Nederland (2024). Farmacotherapeutisch rapport semaglutide (Wegovy®) bij de behandeling van gewichtsbeheersing bij obesitas of overgewicht in combinatie met een comorbiditeit. Report farmacotherapeutischkompas.nl (opens an external site) — accessed 20 October 2026 ↩
European Medicines Agency (2025). PRAC concludes eye condition NAION is a very rare side effect of semaglutide medicines Ozempic, Rybelsus and Wegovy. Regulator ema.europa.eu (opens an external site) — accessed 20 October 2026 ↩
Neeland IJ, Linge J, Birkenfeld AL (2024). Changes in lean body mass with glucagon-like peptide-1-based therapies and mitigation strategies. Diabetes, Obesity and Metabolism 26 Suppl 4:16-27. Review doi:10.1111/dom.15728 (opens an external site) ↩
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