Athlete anti-doping risks

Strict liability — what it means

Under the World Anti-Doping Code, athletes are strictly liable for any prohibited substance found in their sample. Intent does not matter. Contamination does not generally excuse a positive test. “The supplement label didn't say” is not a defence.

For peptides, this matters because:

• Many peptides marketed as “research only” are treated by WADA as prohibited under the S0 non-approved substances category, even when not named individually.
• Growth-hormone secretagogues, growth-factor peptides, and growth-hormone-releasing peptides are explicitly prohibited at all times.
• Unlicensed grey-market product carries elevated contamination risk — a sample contaminated with a prohibited peptide will still produce a positive test.

What WADA's S0 category covers

S0 covers any pharmacological substance that is not addressed by any other section of the Prohibited List and that has no current approval by any governmental regulatory health authority for human therapeutic use. In practice this captures most unlicensed peptides, including those sold as “research peptides”.

Examples of how compounds are commonly treated

The list below is summary-level and is not a substitute for confirming current status with WADA, UKAD, or a qualified anti-doping advisor.

• BPC-157WADA: Prohibited in sport

  Treated by WADA / USADA as prohibited under the S0 (non-approved substances) category.

• TB-500 / Thymosin Beta-4WADA: Prohibited in sport

  Generally treated as prohibited under WADA rules for growth-related, non-approved peptides.

• CJC-1295, Ipamorelin, Sermorelin, GHRPsWADA: Prohibited in sport

  Growth hormone secretagogues — S2 category. Prohibited at all times.

• TesamorelinWADA: Prohibited in sport

  Licensed in some jurisdictions but still falls within WADA's prohibited growth-promoting peptides.

• GLP-1 receptor agonists (semaglutide, tirzepatide, liraglutide)WADA: Sport status unclear

  Used as licensed medicines, but athletes must check current WADA rules and any Therapeutic Use Exemption (TUE) requirements.

• MOTS-c, SS-31, epitalonWADA: Sport status unclear

  Unlicensed and not approved for human use — likely captured by S0 even where not individually named.

What we will not write

• How long a peptide is “detectable”.
• How to time use around testing.
• How to obtain a Therapeutic Use Exemption (TUE) for an unlicensed compound.
• Anything that could be read as anti-doping evasion advice.

We exist to help athletes understand the risk and have informed conversations with their team doctor, sports physician, and anti-doping organisation — not to help them avoid detection.