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Peptides Explained

Sterile technique: keeping germs out of the needle

In short

About 8 minutes for the short version; 12 with every detail open.

  • Germs on hands, tables or vials can get under your skin. Clean steps keep them out.
  • Use a new sterile needle and syringe every time. Never reuse or share them.
  • Wipe the rubber top of the vial with alcohol and let it dry. Then do not touch it.
  • Throw a vial away if it is cloudy, has bits in it, was frozen or is too old.
  • Clean steps cannot fix a product that was dirty from the start.
Last reviewed
A round lab dish split into a clear half and a red half, with creamy white bacterial colonies growing across both.
Colonies of bacteria grown on a lab dish. Photo: CDC / Dr. James Feeley, Centers for Disease Control and Prevention (CDC) (Wikimedia Commons) Public domain Image details

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

Sterile means free of living germs. Aseptic technique is the set of habits that keeps a sterile thing sterile while you use it. Health workers are taught to use these habits for every injection.1,2 This page explains them for someone at home.

This page gives no amounts, volumes or sums. It is about keeping germs out, not about what to inject.

How germs get under the skin

How do germs get in?

A needle carries germs from hands, a table, the skin or the vial into your body.

Germs are too small to see. They live on skin, on tables and in the air. A needle that touches them carries them through the skin, past the body’s first defence.

The short animation shows how germs get in and spread, one step at a time.

Animation · 25 seconds How a needle can carry germs into the body

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

  1. Germs can sit on skin and on the rubber top of a vial. You cannot see them.

    In humans

  2. The needle goes through the skin. It can carry germs into the fat layer underneath.

    In humans

  3. Germs grow under the skin. They may form a pocket of pus (abscess), or redness spreads (cellulitis).

    In humans

  4. Germs can travel along a lymph vessel. Red lines on the skin can be a sign of this.

    In humans

  5. Germs in the blood can cause sepsis. Spreading redness, red lines, fever, feeling very ill? Get help now.

    In humans

In short: A needle can carry germs from the skin, the rubber top of a vial or the liquid into the fat under the skin. There they can form an abscess or cause cellulitis, spread along lymph vessels and reach the blood (sepsis). Spreading redness, red lines, fever or feeling very ill need a doctor straight away. With confusion, very fast breathing or blotchy skin, call your local emergency number.

Lines: solid = shown in people

Based on: World Health Organization (2010)1; Preventing Unsafe Injection Practices3; Safe Injection Practices to Prevent Transmission of Infections to Patients2; Smith et al. (2013)4; Skin abscess5; Cellulitis6; Lymphangitis7; Sepsis8

AI-generated illustration (gpt-image-2.5-sunburst-2026-09-08, 21 October 2026) CC BY 4.0 Image details The picture contains no text; the words, lines and moving marks on it are added by this site.

In detail The same chain in words, with every warning sign
How germs travel from a vial or the skin into the body
  1. Germs are present on the hands, the table, the rubber top of the vial, the skin, or already inside the liquid.
  2. The needle picks them up and carries them into the tissue under the skin.
  3. Under the skin they can grow. The skin around the spot becomes red, hot and swollen: this is a skin infection called cellulitis. Sometimes the body walls the germs off in a pocket of pus: an abscess.
  4. The germs can spread along the lymph vessels and into the blood. In the blood they can cause sepsis, which damages organs and can kill.
  5. Warning signs are spreading redness, heat, swelling, pus, red lines, fever or feeling very ill. Then you need a doctor quickly.

Sources 6, 5, 7, 8, 1

Every step below breaks this chain at one point. Leaving out one step leaves one way in.

Check the product first

What do I check before I start?

The seal, the label, how it looks and how it was kept. Then prepare it cleanly.

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.9,10,4

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.11,12,1

  • 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.13,11

  • 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.14,15

  • 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.16,17,18,19,20

    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.15,21,22,1

    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.1,3,21

  • 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.23,24

    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.25,26,27

    Which checks matter, and whyTalking 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.6,8,28

    All warning signs, and how fast to act

Before you start

What do I do before I start?

Wash your hands, clean a table, and lay out new equipment in sealed packs.
  • Wash your hands with soap and running water for at least 30 seconds. Include the wrists and the spaces between the fingers. Dry them with a clean paper towel. If your hands are not visibly dirty, an alcohol hand rub also works.
  • Clear and clean a table. Remove clutter. Wipe the surface with 70% alcohol and let it dry.
  • Lay out everything you need on the clean surface: a new needle and syringe in sealed packs, alcohol swabs, and a sharps container within reach.
  • Check every pack. Throw away a needle or syringe whose pack is torn, wet or past its expiry date.

Sources 1, 29, 15

Handling the vial

How do I keep the vial clean?

Wipe the rubber top, then do not touch it. Use a new needle and syringe every time.
  • Wipe the rubber top (the stopper) with a fresh alcohol swab. Let it dry in the air before the needle goes in.1
  • Do not touch the stopper after you have wiped it. Do not let the needle touch anything except the stopper and, later, your skin.1
  • Use a new sterile needle and syringe every time you go into a vial. Never put a needle back into a vial after it has been in your skin. Germs and blood from your skin would end up in the whole vial.1,3,21
  • Never leave a needle in the stopper to use it again later.3,1
  • Never share a vial, a syringe, a needle or the water. Hepatitis B, hepatitis C and HIV can pass this way, even when no blood is visible.1,30,31

A needle is also only really sharp the first time. A reused needle is blunter and makes infection more likely.31

Single-dose and multi-dose vials

How long can I use an opened vial?

A single-dose vial: once. A multi-dose vial: usually no more than 28 days after first use.
A single-dose vial is used once. A multi-dose vial is usually thrown away 28 days after first use. Days after first use. Write the date on the vial. A pharmacy medicine may give its own date in the leaflet.

  • Single-dose vial

    open once, then throw away the rest

  • Vial without a preservative

    within 24 hours of opening, unless the maker says otherwise (WHO)

  • Multi-dose vial with a preservative

    throw it away 28 days after first use, unless the maker gives another date (CDC)

  • Compounded GLP-1 medicine in a multi-dose vial (US)

    never past 28 days, even with liquid left or if the instructions say longer (FDA)

Sources Sterile Water for Injection, USP; World Health Organization (2010); Preventing Unsafe Injection Practices; FDA's concerns with unapproved GLP-1 drugs used for weight loss12,1,3,21

In detail Why a multi-dose vial carries more risk, and how to date it

A single-dose vial usually has no preservative. It is meant to be opened once. Whatever is left must be thrown away, because germs that get in can grow freely.12,3

A multi-dose vial is used several times. It usually contains a preservative that slows the growth of bacteria. But the preservative does not work against viruses, and it does not fully protect against bacteria either.3 Every time a needle goes through the stopper, there is a new chance for germs to get in. That is why health workers use multi-dose vials only when there is no other option.1

If you use a multi-dose vial:

  • Write the date on it when you first use it.
  • Throw it away 28 days after first use. A medicine from a pharmacy may have its own date in the leaflet; follow that.3
  • For compounded GLP-1 medicines in multi-dose vials, the FDA is stricter. Throw the vial away 28 days after first use, even if there is liquid left. Do this even if the instructions say you can use it for longer.21
  • A vial without a preservative should be thrown away much sooner. WHO advises within 24 hours of opening, unless the maker says otherwise.1

Bacteriostatic water and sterile water

What water can I mix a powder with?

Only water made for injection. One kind may be opened more than once; the other may not.

Some products come as a powder that must be dissolved before use. Only use water made for injection, from a sealed container. Never use tap water or bottled drinking water.1,30

There are two kinds:

With a preservative, the water can be opened more than once. It cannot make a dirty vial clean. The two kinds of water made for injection, from their US labels and the CDC.
Sterile water for injectionBacteriostatic water
What is in it: is there a preservative?No Only sterile waterYes Sterile water with a preservative (benzyl alcohol)
How often you may open it: more than once?No Once. Throw away the rest.Yes Several times, as a multi-dose container
What the preservative does: does it kill viruses or clean a dirty vial?No Not applicable: there is no preservativeNo Slows the growth of bacteria. Does not kill viruses and does not make a dirty vial clean.

Sources 12, 32, 3

Benzyl alcohol is harmful for newborn babies, so bacteriostatic water must never be used for them.32

Mixing a powder with water

How do I mix a powder without harming it?

Let the water run down the inside wall, then roll or swirl gently. Do not shake.

The same rules apply as for any vial. Wipe both stoppers. Use a new sterile needle and syringe.1

Mix by rolling or swirling the vial gently, never by shaking it
  • Let the water run slowly down the inside wall of the vial.
  • Mix by gently rolling or swirling the vial. Do not shake it.
  • When it is dissolved, the liquid should be clear and without bits. If it is not, do not use it.

Sources 14, 30

Mixing your own vial also means working out amounts. Mistakes happen, and some have been serious.33 This site gives no amounts. A pharmacist or doctor can check your understanding of a prescribed medicine.

In detail Why shaking can harm a peptide

Why not shake? Peptides are fragile chains. Shaking and changes in temperature can make them clump together (aggregate).34 Clumped peptide can lose its activity .34 Clumps in protein medicines have also been linked to immune reactions in patients .35

In detail Dosing mistakes the FDA has seen

The FDA has reports of people who injected 5 to 20 times the intended amount of compounded semaglutide from multi-dose vials. Most were not used to measuring with a syringe. Others had been given wrong conversions between milligrams, millilitres and “units”. Some needed hospital care.33

Storage and the cold chain

How should it be stored?

Follow the leaflet. Changes in temperature and shaking can break a peptide down.

Wegovy, for example, belongs in the fridge and must not freeze

2–8 °C

in the fridge, says the Wegovy label. Keep it away from the cooling element.

Who took part EU product information for Wegovy, one example of a peptide medicine label Source Wegovy (semaglutide)15 Evidence Established

The cold chain means keeping a medicine cold at every step, from the factory to your fridge.

For products from outside a pharmacy, nobody knows how they were stored or shipped. The FDA has received complaints about compounded GLP-1 products that arrived warm or with too few ice packs. It advises not to use an injectable GLP-1 product that arrives warm.21

In detail What the Wegovy label says, and why temperature matters

Authorised peptide medicines come with clear storage rules. The Wegovy label is an example. Store it in the fridge (2–8 °C), away from the cooling element. Out of the fridge, it may be kept below 30 °C only for the time the leaflet states. Do not freeze it. Protect it from light. Do not use it if it has been frozen or left in direct sunlight.15

The reason is chemistry. Changes in temperature and shaking can break peptides down or make them clump .22,34 A freeze-dried powder is usually more stable than a liquid. But freeze-drying itself can make some peptides clump more after mixing.34

When to throw a vial away

When should I throw a vial away?

When it looks wrong, was stored wrong, is too old, or may have germs in it.
  • It should be clear, but it is cloudy, coloured, or has bits or flakes in it.
  • The vial is cracked, or the seal or cap is broken or missing.
  • It has been frozen, or left warm or in the sun.
  • It is a multi-dose vial more than 28 days after first use, or it has no date.
  • You touched the stopper, or the needle touched something else.
  • A used needle went into it, or someone else used it.
  • You do not know how old it is or how it was stored.

Sources 15, 14, 12, 1, 3, 21

When in doubt, throw it out.

Why a powder is not proof of sterility

Is a dry powder sterile?

Not by itself. Freeze-drying does not kill germs.

Germs were found in vials that had never been opened

749

people had infections by 1 July 2013, and 61 of them died

Who took part US outbreak investigation, 2012–2013: fungal infections after steroid injections from one pharmacy Source Smith et al. (2013)4 Evidence Humans, limited

Many people trust a freeze-dried powder because it looks dry and clean. But dry and clean-looking does not mean free of germs.

So sterile technique protects you from germs you might add. It cannot remove germs that were already in the product. See product risk.

In detail What freeze-drying does, and how a factory makes a powder sterile

Freeze-drying removes water from a frozen product. It does not kill germs. In fact, laboratories use freeze-drying to keep collections of bacteria alive.36

In a proper factory, sterility comes from other steps. The liquid is passed through a filter that holds back bacteria. The vials are filled in germ-free conditions. The freeze-dryer itself is sterilised. Regulators inspect these steps.37 If they are skipped, the powder can carry germs and bacterial toxins (endotoxins), and you cannot see them.37

Germs are not the only thing that can be wrong. The plate shows six problems a vial from outside a pharmacy may have.

What may be wrong with a vial bought online

Key

  1. May not be what the label says The FDA warns that one name can cover different salt forms, or even a different active substance. A French lab found that products sold as TB-500 did not always match their description.
  2. The amount may differ from the label A 2026 study in Australia tested 3 products sold as retatrutide. They held from about half to almost twice the amount on the label. The TB-500 certificates the FDA saw did not check the amount.
  3. May hold near-copies and leftover chemicals Making a peptide can leave chains that are too short or slightly wrong, plus leftover solvents and other chemicals. Most certificates the FDA saw gave the purity but did not say which impurities were there.
  4. May not be tested for bacterial toxins (endotoxin) For anything injected, the FDA says this test is key. The certificates it saw for BPC-157 and TB-500 did not have it.
  5. May not be tested for germs For injections, the FDA says germ tests are key too. The certificates it saw for BPC-157, KPV and TB-500 showed no germ tests.
  6. Clumps may make immune reactions more likely Peptides can stick together into clumps. The FDA says clumps and impurities may raise the risk of an immune reaction, from harmless to life-threatening. No study has tested this for BPC-157, KPV or TB-500.
In words

The picture shows one small glass vial with a grey rubber stopper and some white powder at the bottom. It has no label. Six numbers show what may be wrong with a vial like this when it is bought online. Number 1, on the glass where a label would be: it may not be what the label says. The FDA warns that one name can cover different salt forms, or even a different active substance. A French lab found that products sold as TB-500 did not always match their description. Number 2, on the powder: the amount may differ from the label. A 2026 study in Australia tested 3 products sold as retatrutide. They held from about half to almost twice the amount on the label. The TB-500 certificates the FDA saw did not check the amount. Number 3, on the powder: making a peptide can leave chains that are too short or slightly wrong, plus leftover solvents and other chemicals. Most certificates the FDA saw gave the purity but did not say which impurities were there. Number 4, inside the vial: it may not have been tested for bacterial toxins, called endotoxin. For anything injected, the FDA says this test is key, and the certificates it saw for BPC-157 and TB-500 did not have it. Number 5, inside the vial: it may not have been tested for germs. For injections the FDA says germ tests are key too, and the certificates it saw for BPC-157, KPV and TB-500 showed no germ tests. Number 6, on the powder: peptides can stick together into clumps. The FDA says clumps and impurities may raise the risk of an immune reaction, from harmless to life-threatening. No study has tested this for BPC-157, KPV or TB-500. That is why number 6 has a different colour: it is a possible risk, not a proven one.

Based on: FDA Briefing Document for BPC-157-Related Bulk Drug Substances (BPC-157 (free base) and BPC-157 acetate), Pharmacy Compounding Advisory Committee meeting, 23–24 July 2026; FDA Briefing Document for KPV-Related Bulk Drug Substances (KPV (free base) and KPV acetate), Pharmacy Compounding Advisory Committee meeting, 23-24 July 2026; FDA Briefing Document for TB-500-Related Bulk Drug Substances (TB-500 (free base) and TB-500 acetate), Pharmacy Compounding Advisory Committee meeting, 23–24 July 2026; Piatkowski et al. (2026); Delcourt et al. (2023)

AI-generated illustration (gpt-image-2.5-sunburst-2026-09-08, 21 October 2026) CC BY 4.0 Image details The picture contains no text; the numbers and labels are added by this site.

In detail The 2012 outbreak: germs inside unopened vials

A real example shows what this means. In 2012, US health officials traced an outbreak of fungal infections to steroid injections from one pharmacy. Fungus was found in vials that had never been opened. By 1 July 2013, 749 people had infections and 61 had died.4 The problem was not how the injections were given. The germs were inside before anyone used a needle.

Next steps

What should I read next?

How to inject, how to get rid of needles, and when to get help.

Stop-now warning signs

Call your local emergency number now

  • 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).

Get medical help today

  • 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.

Stop and contact a doctor

  • 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.

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 37 sources, numbered as in the text
  1. World Health Organization (2010). WHO best practices for injections and related procedures toolkit (WHO/EHT/10.02). World Health Organization, Geneva. Report who.int — accessed 20 October 2026 ↩
  2. Centers for Disease Control and Prevention (2024). Safe Injection Practices to Prevent Transmission of Infections to Patients. Regulator cdc.gov — accessed 20 October 2026 ↩
  3. Centers for Disease Control and Prevention (2024). Preventing Unsafe Injection Practices. Regulator cdc.gov — accessed 20 October 2026 ↩
  4. Smith RM, Schaefer MK, Kainer MA, Wise M, Finks J, et al. (2013). Fungal infections associated with contaminated methylprednisolone injections. The New England Journal of Medicine 369:1598-1609. Research article doi:10.1056/NEJMoa1213978 ↩
  5. NHS (England) (2026). Skin abscess. Web page nhs.uk — accessed 20 October 2026 ↩
  6. NHS (England) (2024). Cellulitis. Web page nhs.uk — accessed 20 October 2026 ↩
  7. MedlinePlus Medical Encyclopedia (U.S. National Library of Medicine) (2025). Lymphangitis. Web page medlineplus.gov — accessed 20 October 2026 ↩
  8. NHS (England) (2026). Sepsis. Web page nhs.uk — accessed 20 October 2026 ↩
  9. Inspectie Gezondheidszorg en Jeugd (IGJ) (2026). Online medicijnen. Regulator igj.nl — accessed 22 October 2026 ↩
  10. Ashraf AR, Mackey TK, Vida RG, Kulcsár G, Schmidt J, Balázs O, Domián BM, Li J, Csákó I, Fittler A (2024). Multifactor Quality and Safety Analysis of Semaglutide Products Sold by Online Sellers Without a Prescription: Market Surveillance, Content Analysis, and Product Purchase Evaluation Study. Journal of Medical Internet Research 26:e65440. Research article doi:10.2196/65440 ↩
  11. U.S. Food and Drug Administration (2020). BeSafeRx: Considering an Online Pharmacy?. Regulator fda.gov — accessed 22 October 2026 ↩
  12. Hospira, Inc. / DailyMed (National Library of Medicine) (2026). Sterile Water for Injection, USP: prescribing information. Official product information dailymed.nlm.nih.gov — accessed 20 October 2026 ↩
  13. European Parliament and Council of the European Union (2001). Directive 2001/83/EC on the Community code relating to medicinal products for human use (consolidated text). Official Journal of the European Communities, L 311. Law eur-lex.europa.eu — accessed 20 October 2026 ↩
  14. U.S. Food and Drug Administration / DailyMed (National Library of Medicine) (2026). EGRIFTA SV (tesamorelin for injection): prescribing information and instructions for use. Official product information dailymed.nlm.nih.gov — accessed 20 October 2026 ↩
  15. European Medicines Agency (2026). Wegovy (semaglutide): EPAR — overview and product information. Official product information ema.europa.eu — accessed 20 October 2026 ↩
  16. European Medicines Agency (ICH) (2000). ICH Q7 Good manufacturing practice for active pharmaceutical ingredients (CPMP/ICH/4106/00). European Medicines Agency, scientific guideline. Regulator ema.europa.eu — accessed 22 October 2026 ↩
  17. European Medicines Agency, CHMP and CVMP (2025). Guideline on the Development and Manufacture of Synthetic Peptides (EMA/CHMP/CVMP/QWP/367182/2025). European Medicines Agency. Regulator ema.europa.eu — accessed 22 October 2026 ↩
  18. U.S. Food and Drug Administration (2026). FDA Briefing Document for BPC-157-Related Bulk Drug Substances (BPC-157 (free base) and BPC-157 acetate), Pharmacy Compounding Advisory Committee meeting, 23–24 July 2026. Regulator fda.gov — accessed 20 October 2026 ↩
  19. U.S. Food and Drug Administration (2026). FDA Briefing Document for TB-500-Related Bulk Drug Substances (TB-500 (free base) and TB-500 acetate), Pharmacy Compounding Advisory Committee meeting, 23–24 July 2026. Regulator fda.gov — accessed 20 October 2026 ↩
  20. Janvier S, Cheyns K, Canfyn M, Goscinny S, De Spiegeleer B, Vanhee C, Deconinck E (2018). Impurity profiling of the most frequently encountered falsified polypeptide drugs on the Belgian market. Talanta 188:795-807. Research article doi:10.1016/j.talanta.2018.06.023 ↩
  21. U.S. Food and Drug Administration (2026). FDA's concerns with unapproved GLP-1 drugs used for weight loss. Regulator fda.gov — accessed 20 October 2026 ↩
  22. Manning MC, Chou DK, Murphy BM, Payne RW, Katayama DS (2010). Stability of protein pharmaceuticals: an update. Pharmaceutical Research 27:544-575. Review doi:10.1007/s11095-009-0045-6 ↩
  23. NHS (2025). Poisoning. Web page nhs.uk — accessed 22 October 2026 ↩
  24. Antonacci G, Bortignon E, Bolognesi M, Piano SS, Cadore A, Camuffo L, Venturini F, Faoro S, Favretto D, Romano A, Mengato D (2026). Hypoglycaemic coma induced by a falsified semaglutide product: a case report. European Journal of Hospital Pharmacy 33:486-489. Research article doi:10.1136/ejhpharm-2025-004656 ↩
  25. Thuisarts.nl (Nederlands Huisartsen Genootschap, NHG) (2024). Ik ga naar de huisarts: wat kan ik van tevoren doen en verwachten?. Web page thuisarts.nl — accessed 22 October 2026 ↩
  26. Department of Health, Victoria (Australia), Chief Health Officer (2026). Toxicity linked to unapproved peptide product labelled Retatrutide (health alert). Regulator health.vic.gov.au — accessed 22 October 2026 ↩
  27. KNMG (Royal Dutch Medical Association) (2024). Medisch beroepsgeheim: wat en waarom. Web page knmg.nl — accessed 20 October 2026 ↩
  28. NHS (England) (2023). Anaphylaxis. Web page nhs.uk — accessed 20 October 2026 ↩
  29. Rijksinstituut voor Volksgezondheid en Milieu (RIVM), Landelijk Centrum Hygiëne en Veiligheid (2026). Hygiënerichtlijn voor piercen. Regulator rivm.nl — accessed 20 October 2026 ↩
  30. Stichting Mainline (2023). Veilig injecteren van anabole steroïden. Web page mainline.nl — accessed 20 October 2026 ↩
  31. Trimbos-instituut (DRUGSinfo) (2026). Injecteren (spuiten/slammen): risico's verminderen. Web page drugsinfo.nl — accessed 20 October 2026 ↩
  32. Hospira, Inc. / DailyMed (National Library of Medicine) (2026). Bacteriostatic Water for Injection, USP: prescribing information. Official product information dailymed.nlm.nih.gov — accessed 20 October 2026 ↩
  33. 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 — accessed 20 October 2026 ↩
  34. Zapadka KL, Becher FJ, Gomes Dos Santos AL, Jackson SE (2017). Factors affecting the physical stability (aggregation) of peptide therapeutics. Interface Focus 7:20170030. Review doi:10.1098/rsfs.2017.0030 ↩
  35. Rosenberg AS (2006). Effects of protein aggregates: an immunologic perspective. The AAPS Journal 8:E501-E507. Review doi:10.1208/aapsj080359 ↩
  36. Morgan CA, Herman N, White PA, Vesey G (2006). Preservation of micro-organisms by drying; a review. Journal of Microbiological Methods 66:183-193. Review doi:10.1016/j.mimet.2006.02.017 ↩
  37. U.S. Food and Drug Administration (1993). Lyophilization of Parenteral (7/93): Guide to Inspections. Regulator fda.gov — accessed 20 October 2026 ↩