Peptides and Anti-Doping: WADA Status Explained

If you compete in a sport governed by the World Anti-Doping Code, the peptide question is simpler than most: a large share of popular research peptides are prohibited, many of them at all times, and a positive test can cost you years of eligibility. This guide explains where peptides land on the WADA Prohibited List and what the categories actually mean. It is not medical or legal advice.

The Prohibited List is built around categories, not brand names

WADA publishes a Prohibited List each year (the current one took effect January 1, 2026). Substances are grouped into classes — S0 through S9 plus prohibited methods — and a compound is banned if it fits a class, even when it is not named. For the peptide classes, the list prohibits the named substances “and other substances with similar chemical structure or similar biological effect(s),” so the absence of a peptide from the printed list does not make it allowed.

Two timing tiers matter. Substances prohibited at all times are banned both in- and out-of-competition, year-round. Substances prohibited in-competition only are banned during the in-competition period, which the Code defines as beginning at 11:59 p.m. on the day before a competition through the end of that competition and its sample-collection process. The peptide classes that concern most readers are prohibited at all times.

S2: peptide hormones, growth factors, and their releasing factors

S2 is where most well-known peptides sit, and it is prohibited at all times. On the 2026 List, S2 is organized as follows:

Erythropoietins (EPO) and agents affecting erythropoiesis (S2.1) — EPO receptor agonists, HIF-activating agents, and related substances.
Peptide hormones and their releasing factors (S2.2), which includes:
- Testosterone-stimulating peptides in males, e.g. chorionic gonadotrophin (CG), luteinizing hormone (LH), GnRH (gonadorelin) and its agonist analogues, and kisspeptin.
- Corticotrophins and their releasing factors.
- Growth hormone (GH), its analogues and fragments (e.g. AOD-9604, hGH 176-191).
- Growth hormone releasing factors — GHRH and its analogues (e.g. CJC-1293, CJC-1295, sermorelin, tesamorelin), GH secretagogues such as ipamorelin (and ibutamoren/MK-677, anamorelin, others), and GH-releasing peptides (GHRPs) such as hexarelin, GHRP-1, GHRP-2 (pralmorelin), and GHRP-6.
Growth factors and growth factor modulators (S2.3) — including IGF-1 and its analogues, mechano growth factors (MGFs), fibroblast growth factors, hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), and any growth factor affecting muscle, tendon, or ligament protein synthesis, vascularisation, or regenerative capacity. Thymosin-β4 and its derivatives, including TB-500, are named explicitly here.

The practical takeaway: the “healing” and “GH-boosting” peptides marketed to athletes are largely S2 and prohibited at all times.

S0: non-approved substances (where BPC-157 lives)

S0 captures any pharmacological substance not addressed by another section of the List and “with no current approval by any governmental regulatory health authority for human therapeutic use” — drugs in preclinical or clinical development, discontinued drugs, designer drugs, and substances approved only for veterinary use. On the 2026 List, BPC-157 is named explicitly as an example of an S0 substance, and it is prohibited at all times. USADA likewise states BPC-157 is prohibited under S0, noting it “is not approved for human clinical use by any global regulatory authority.” Because S0 substances have no approved therapeutic use, a Therapeutic Use Exemption is realistically not available for them.

S4: hormone and metabolic modulators

Some peptide-adjacent compounds appear in S4, which is also prohibited at all times. The classes most relevant to peptide users are:

Agents preventing activin receptor IIB activation (S4.3) — myostatin inhibitors, including myostatin-binding proteins such as follistatin and myostatin propeptide, myostatin- or precursor-neutralising antibodies, and decoy activin receptors such as ACE-031.
Metabolic modulators (S4.4) — including AMPK activators such as AICAR and the mitochondrially derived peptide MOTS-c.

Therapeutic Use Exemptions (TUEs)

A TUE allows an athlete to use a prohibited substance for a genuine medical condition. Under the WADA International Standard for TUEs, four conditions must all be met: the substance treats a diagnosed condition supported by clinical evidence; it would not produce performance enhancement beyond a return to normal health; there is no reasonable permitted alternative; and the need is not a consequence of prior use of a prohibited substance without a TUE. Applications require detailed medical documentation and are reviewed by an independent TUE Committee, which is expected to decide within 21 days of receiving a complete application. Substances with no approved medical use — most S0 research peptides — realistically cannot qualify.

Bottom line

In tested sport, assume a peptide is banned until you have personally confirmed otherwise. EPO, GH and its releasing peptides (GHRH analogues, GHRPs, ipamorelin), growth factors like TB-500, myostatin-related agents, and unapproved peptides like BPC-157 are prohibited — most of them at all times — and many carry multi-year sanctions. Check each specific substance and product on Global DRO (note that it does not cover dietary supplements), and route any genuine medical need through the TUE process before use, not after a positive test.