Peptides Explained

Peptides Explained

In short

Reading the whole page takes about 3 minutes.

  • This site explains therapeutic peptides: what they are, what the research really shows, and what the law says.
  • It sells nothing and links to no seller. It is not a dosing guide.
  • Some peptides are approved medicines. Many sold online were never tested well in people.
  • If you feel unwell after using a peptide, read the warning signs page now.
Last reviewed
Clear crystals with many flat sides, some stacked together, on a pale blue background under a microscope.
Insulin crystals, seen up close. The photo comes from NASA. Photo: NASA/Marshall, NASA Marshall Space Flight Center (photo ID 9901879) (Wikimedia Commons) Public domain Image details

The most important distinction

Does the same name mean the same product?

No. The same name can mean a checked medicine or an unchecked vial.
A pharmacy medicine and an online vial can share a name. They are not the same thing. Semaglutide as an example. What regulators say about each.
Semaglutide from a pharmacy“Research semaglutide” sold online
An authorised medicine?Yes Authorised in the EU; only on prescription1,2,3No It is not that medicine. The UK regulator says GLP-1 powder in vials is not authorised4
Benefits and risks weighed by a regulator?Yes Before it was authorised3,5No The US regulator says it does not check these copies for harm, effect or quality6
Is what is inside checked?Yes The EU regulator checked how well it is made before it was allowed3No No regulator has checked what is in it. The Dutch regulator says it is unclear what is inside5,6

The same name can mean two very different things. Semaglutide from a pharmacy is an authorised medicine: a regulator has checked its quality, its effects and its risks.3,5 A vial sold online as “research semaglutide” is not that medicine. No regulator has checked what is in it.5,6

Most of the other peptides people talk about, such as BPC-157, have no authorisation anywhere.7,8,9 Their evidence comes mostly from animals.7 This site shows the shape of that evidence for every compound, in the same way, so you can compare honestly.

Who this is for

Who is this site for?

Anyone who uses peptides, is curious, gets asked about them, or is worried about someone.
Who you areA good place to start
People who have decided to use a peptide, or already do, and want to lower the risk.Before you consider a peptide, the checks before you use a product, then the warning signs
People who are curious and want to know what they don’t know.Start here
Doctors, physiotherapists and trainers who keep getting asked.All compounds, each with the same evidence profile
Partners and parents who are worried.The warning signs and talking to your doctor

Where to start

Where should I begin?

Read Start here first. It covers what everyone needs to know first.

To look up a compound, see all compounds. For headlines from regulators and research indexes, see research news.

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.

  1. European Medicines Agency (2026). Ozempic (semaglutide): EPAR — overview and product information. Official product information ema.europa.eu — accessed 20 October 2026 ↩
  2. European Medicines Agency (2026). Rybelsus (semaglutide): EPAR — overview and product information. Official product information ema.europa.eu — accessed 20 October 2026 ↩
  3. European Medicines Agency (2026). Wegovy (semaglutide): EPAR — overview and product information. Official product information ema.europa.eu — accessed 20 October 2026 ↩
  4. 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 — accessed 20 October 2026 ↩
  5. College ter Beoordeling van Geneesmiddelen (CBG-MEB) (2026). Standpunt: Gebruik diabetes- en afslankmedicijnen alleen zoals ze bedoeld zijn. Regulator cbg-meb.nl — accessed 20 October 2026 ↩
  6. 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 ↩
  7. 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 ↩
  8. 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 ↩
  9. European Medicines Agency (2026). Medicines (search of centrally authorised medicines and EPARs). Regulator ema.europa.eu — accessed 20 October 2026 ↩