Which peptides are on the WADA prohibited list?

This comes up constantly and gets answered badly, usually by someone conflating it with the legal question. They are separate, they are decided by different bodies, and the anti-doping answer is almost always the stricter of the two.

Nothing here is guidance about use. It is a description of how a set of rules classifies a set of substances, for material supplied for laboratory research use only.

Prohibited is not the same as tested for

The single most common error is treating these as one question.

Prohibited means the substance appears on the World Anti-Doping Agency's list, which is republished every year and takes effect on 1 January. Tested for means a validated assay exists and the laboratory ran it on that sample.

A substance can be prohibited for years before a routine assay exists, and stored samples can be retested later under rules that allow a sample to be reanalysed for up to ten years. "There is no test for it" has never been a defence, and several athletes have been sanctioned years after the fact when a method caught up with a sample sitting in a freezer.

The corollary: any answer along the lines of "it does not show up" is a statement about this season's assay menu, not about the rules.

The categories that matter here

S0 — Non-approved substances. The catch-all, and the one people forget. It covers any pharmacological substance with no current approval by any governmental regulatory health authority for human therapeutic use. Prohibited at all times, in and out of competition. Most research peptides land here by default precisely because they are unapproved — the same fact that makes them lawful to hold for research is what puts them in S0.

S2 — Peptide hormones, growth factors, related substances and mimetics. The explicit category. It names growth hormone and its releasing factors, which is where the GHRH analogues sit, along with a range of growth factors affecting tissue synthesis and regeneration.

S4 — Hormone and metabolic modulators. Relevant for some metabolic agents.

Both S0 and S2 are prohibited at all times, not merely in competition. That distinction matters more than anything else on this page: out-of-competition testing exists precisely for substances whose benefit accrues during training.

Compound by compound

BPC-157 — prohibited. WADA added it explicitly in recent years; before that it was caught by S0 as an unapproved substance. Either route reaches the same place, and it is prohibited at all times.

TB-500 / thymosin beta-4 — prohibited under S2 as a growth factor affecting tissue regeneration. This one has a long enforcement history and is not a borderline case.

CJC-1295 and other GHRH analogues — prohibited under S2, which names growth hormone releasing factors directly. The least ambiguous entry here.

Tesamorelin — a GHRH analogue, so S2, notwithstanding that it holds a US approval for one specific indication.

MOTS-C — unapproved everywhere, so S0 at minimum.

GHK-Cu — the genuinely unclear one. A copper-binding tripeptide with a long history in cosmetic formulation, and topical cosmetic use is not obviously within scope. Injectable use of an unapproved preparation is a different matter and S0 is the obvious reading. If this question is live for you, ask your anti-doping body rather than a supplier.

KPV — unapproved, so S0 at minimum.

Tirzepatide and semaglutide — approved medicines, which takes them out of S0. Whether a metabolic modulator category applies is a live question and has been discussed in anti-doping circles as these drugs have become widespread. Approved status is not a clearance.

Retatrutide — investigational and approved nowhere, so squarely S0.

The NCAA and other bodies run their own lists

WADA is not the only rulebook. The NCAA publishes its own list of banned drug classes, and so do individual sports federations, professional leagues, the military, and some employers. They overlap heavily but they are not identical, and the one that binds you is the one for your sport or organisation.

A compound being absent from one body's list says nothing about another's.

Strict liability

The principle underpinning all of it: an athlete is responsible for what is found in their sample. Not for what they intended to take, not for what the label said, and not for what a vendor told them.

That has a specific consequence in this market. Contamination and mislabelling are real and documented — independent testing has repeatedly found products whose contents differ from their labels, sometimes containing a different compound entirely. Under strict liability, the consequence of that lands on the athlete, not the seller.

Which is the one place this connects to what we do. It is not an argument for using anything; it is an argument that if you are subject to testing, "I did not know what was in it" is not a position the rules recognise. What an independent laboratory report establishes is what is actually in a specific batch — and how to get a peptide independently tested in the UK covers doing that yourself.

Where to check

The Prohibited List is published annually by WADA and is the authoritative source. National anti-doping organisations run checking services for their athletes — in the UK that is UK Anti-Doping's Global DRO. Those are the places to get an answer that means anything. A supplier is not, including this one.

The separate question of what is lawful to buy and hold in the UK is covered in are research peptides legal in the UK, and regulatory approval status compound by compound in FDA approved, MHRA licensed, or neither.