The WADA Prohibited List and Peptides: Which Classes Are Named

Research-use-only context. This article summarizes published third-party scientific literature and laboratory practice. It is not medical advice, not a therapeutic or performance claim, and not a usage guide. US Prime Peptides products are supplied strictly for in vitro laboratory research and are not for human or veterinary use.

The World Anti-Doping Agency (WADA) Prohibited List names several peptides that also appear in research catalogs, and it does so by class rather than by a single alphabetical roster. This article explains how the 2026 List is organized, quotes the three classes that capture most research peptides (S0, S2, and S4), maps common catalog compounds to the class that names them, and explains why anti-doping and sports-science laboratories work with characterized reference materials. Inclusion on the List is a regulatory fact about sport; it is not evidence that a compound does anything in people.

What the Prohibited List is and how it is organized

The Prohibited List is the international standard, maintained by WADA, that identifies the substances and methods prohibited in sport. It is revised every year, and each edition takes effect on January 1; the 2026 edition was published on September 24, 2025 and states that it "shall come into effect on 1 January 2026." The List divides substances into numbered classes. Those prohibited at all times, in and out of competition, are S0 "Non-approved substances," S1 "Anabolic agents," S2 "Peptide hormones, growth factors, related substances, and mimetics," S3 "Beta-2 agonists," S4 "Hormone and metabolic modulators," and S5 "Diuretics and masking agents," plus the prohibited methods M1 through M3. Classes S6 through S9 are prohibited in competition only, and P1 covers beta-blockers in particular sports.

Two features of the List matter for reading it correctly. First, every class is written as "including, but not limited to," followed by a closing clause that sweeps in "other substances with a similar chemical structure or similar biological effect(s)." A compound that is not named can still be prohibited. Second, each class is flagged as containing either "Specified" or "non-Specified" substances, a distinction that affects how a sanction is handled rather than whether the substance is prohibited. S0 substances are Specified; S2 and S4 substances are non-Specified. The sections below quote the class names exactly and paraphrase the definitions.

S0, Non-approved substances: the catch-all that names BPC-157

Class S0 covers any pharmacological substance that is not addressed by a later section of the List and that has no current approval from any governmental regulatory health authority for human use. The List gives examples of what that means in practice: drugs under pre-clinical or clinical development, discontinued drugs, designer drugs, and substances approved only for veterinary use. The 2026 text then states that "this class covers many different substances including but not limited to BPC-157," alongside 2,4-dinitrophenol (DNP), ryanodine receptor-calstabin complex stabilizers such as S-107, and troponin activators such as reldesemtiv.

BPC-157 is the only peptide named in S0, but the class is defined by approval status, not by a list. A peptide that has never been approved anywhere, and is not captured by S2 or S4, falls under S0 by definition. The US Anti-Doping Agency's explainer on BPC-157 makes the same point from the athlete's side: the compound is prohibited "in the category of S0 Non-Approved Substances," there are no human clinical trials establishing efficacy for any indication, and the available evidence comes largely from animal studies. That framing mirrors how a research supplier should present the compound: a pentadecapeptide with a rodent and cell-culture literature, no approval anywhere, and a research-use-only label. A separate article covers what the BPC-157 literature actually contains.

S2, Peptide hormones, growth factors, related substances, and mimetics

Class S2 is where most research-catalog peptides appear, and it is organized into three numbered groups. S2.1 covers erythropoietin and agents affecting erythropoiesis, including EPO receptor agonists (the 2026 List added pegmolesatide as an example), hypoxia-inducible factor activators such as roxadustat, and the innate repair receptor agonists asialo-EPO and carbamylated EPO. S2.2 covers "peptide hormones and their releasing factors," and S2.3 covers "growth factors and growth factor modulators."

S2.2 is subdivided. S2.2.1 names testosterone-stimulating peptides in males, including chorionic gonadotrophin, luteinizing hormone, "gonadotrophin-releasing hormone (GnRH, gonadorelin) and its agonist analogues," and "kisspeptin and its agonist analogues." S2.2.3 names growth hormone, its analogues, and its fragments, with "AOD-9604 and hGH 176-191" given as examples of fragments. S2.2.4, "growth hormone releasing factors," is the densest paragraph for a research buyer: it lists "growth hormone-releasing hormone (GHRH) and its analogues (e.g. CJC-1293, CJC-1295, sermorelin and TH9507)," growth hormone secretagogues and their mimetics including anamorelin, ibutamoren (MK-677), ipamorelin, lenomorelin (ghrelin), and macimorelin, and the GH-releasing peptides, "GHRP-1, GHRP-2 (pralmorelin), GHRP-3, GHRP-4, GHRP-5 and GHRP-6," along with alexamorelin and examorelin (hexarelin).

S2.3 names fibroblast growth factors, hepatocyte growth factor, "insulin-like growth factor 1 (IGF-1, mecasermin) and its analogues," mechano growth factors, platelet-derived growth factor, "thymosin-β4 and its derivatives e.g. TB-500," and vascular endothelial growth factor. Its closing clause extends the class to any other growth factor or modulator affecting muscle, tendon, or ligament protein synthesis or degradation, vascularisation, energy utilization, regenerative capacity, or fibre-type switching. A research vial of a 43-residue thymosin beta-4 fragment is therefore named on the List even though the research literature on it, summarized in our TB-500 overview, is almost entirely preclinical.

S4, Hormone and metabolic modulators: where MOTS-c appears

Class S4 covers four groups: S4.1 aromatase inhibitors, S4.2 anti-estrogenic substances, S4.3 agents preventing activin receptor IIB activation (myostatin inhibitors and related antibodies), and S4.4 "metabolic modulators." It is S4.4 that reaches into peptide catalogs. S4.4.1 lists "activators of the AMP-activated protein kinase (AMPK)," with the examples BAM15, AICAR, and "mitochondrial open reading frame of the 12S rRNA-c (MOTS-c)," followed by PPAR-delta agonists such as GW1516 and Rev-erb-alpha agonists such as SR9009. S4.4.2 covers insulins and insulin-mimetics, S4.4.3 meldonium, and S4.4.4 trimetazidine.

The 2026 edition is notable for adding two substances to S4 that WADA and the US Anti-Doping Agency specifically describe as having been found in supplements and products marketed as "research chemicals": 2-phenylbenzo[h]chromen-4-one (alpha-naphthoflavone), an aromatase inhibitor added to S4.1, and BAM15, added to S4.4.1. Flmodafinil and fladrafinil, modafinil analogs sold as "research only" products, were added to the in-competition stimulant class S6 at the same time. The pattern is clear: WADA now watches the research-chemical market and adds named examples when a product gains circulation. MOTS-c, a 16-residue mitochondrial-derived peptide, is a case in point; it sits in S4.4.1 because of the AMPK-related mechanism reported in cell and rodent studies, not because of any human outcome data, and our MOTS-c overview explains where that literature stands.

Reference table: common research peptides and the class that names them

The table maps catalog compounds to the 2026 List as quoted above. "Named" means the compound or its parent appears as an example in that class; "by definition" means it is captured by the S0 definition or a class's closing clause rather than by name. Absence from this table is not clearance; the List's "including, but not limited to" language and the S0 catch-all apply to everything.

Why this matters for sports-science and anti-doping laboratories

Anti-doping laboratories cannot detect what they cannot characterize, which is why small-peptide reference materials are a research category in their own right. A 2021 review in the Journal of Chromatography B traced a decade of progress in doping-control analysis of small peptides, covering the sample preparation, liquid chromatography, and mass spectrometry workflows that identify growth hormone releasing peptides and related sequences in biological matrices. An earlier 2014 review in the Journal of Pharmaceutical and Biomedical Analysis set out the analytical approaches for emerging and non-approved compounds, the same category S0 describes.

The reference-material problem is also a provenance problem. A 2010 Drug Testing and Analysis paper reported the identification of GHRP-2 in a product sold as a nutritional supplement, and a 2014 European Journal of Clinical Pharmacology study catalogued black-market products seized in Germany between 2010 and 2013, including peptide preparations whose labels did not match their contents. A 2021 Forensic Science International analysis of products seized from bodybuilding circles reached similar conclusions, and a 2026 critical review in the Journal of Sports Medicine and Physical Fitness surveyed the growing use of peptide and peptide-analog products in recreational and professional sport. Each of these papers depended on laboratories that could obtain a correctly identified reference standard, confirm it by mass spectrometry, and quantify its purity before comparing it to a seized sample.

That is the legitimate research intersection between the Prohibited List and a research-peptide catalog: method development, reference characterization, and stability work. It requires a vial whose identity has been confirmed by mass spectrometry and whose purity and net peptide content are stated on a lot-matched certificate, which is why the identity line on a certificate matters more to an analytical laboratory than any other line. US Prime Peptides supplies these compounds strictly for in vitro research under a physician-use, research-use-only model; nothing in this article should be read as describing or endorsing their use by athletes or anyone else.

Frequently Asked Questions

Is BPC-157 on the WADA Prohibited List?

Yes. The 2026 List names BPC-157 as an example under class S0, "Non-approved substances," which covers pharmacological substances with no current approval from any governmental regulatory health authority for human use. S0 substances are prohibited at all times, in and out of competition.

Which peptides are banned under WADA S2?

Class S2, "Peptide hormones, growth factors, related substances, and mimetics," names GnRH (gonadorelin) and kisspeptin analogues, growth hormone fragments such as AOD-9604, GHRH analogues including CJC-1295, sermorelin, and TH9507, growth hormone secretagogues including ipamorelin and ibutamoren, the GHRPs (GHRP-1 through GHRP-6 and hexarelin), IGF-1 and its analogues, and thymosin beta-4 and its derivatives such as TB-500. The class also covers unnamed substances with similar structure or effect.

Is MOTS-c prohibited by WADA?

Yes. MOTS-c is named in S4.4.1 of the 2026 List as an example of an AMP-activated protein kinase activator, alongside AICAR and BAM15, within class S4, "Hormone and metabolic modulators." It is prohibited at all times.

Does being on the WADA list mean a peptide works?

No. The List is a regulatory instrument for sport; WADA adds substances based on potential to enhance performance, health risk, or conflict with the spirit of sport, and S0 explicitly captures compounds with no approval and often no human data at all. Inclusion says nothing about whether the published research supports any effect in people, and for most of the peptides named here that research is preclinical.

Citations

1. World Anti-Doping Agency. The Prohibited List 2026 (in effect 1 January 2026), classes S0, S2 and S4. wada-ama.org
2. German Sport University Cologne, Institute of Biochemistry. S2 Peptide hormones, growth factors, related substances, and mimetics (reproduction of the 2026 List class text, updated June 1, 2026). dshs-koeln.de
3. International Cricket Council. Prohibited List: Substances and Methods Prohibited at All Times (reproduction of classes S0 and S4). icc-cricket.com
4. US Anti-Doping Agency. Athlete Advisory: What's New on the 2026 WADA Prohibited List? usada.org
5. US Anti-Doping Agency. BPC-157: Experimental Peptide Prohibited in Sport. usada.org
6. UK Anti-Doping. The 2026 Prohibited List: Summary of Changes. ukad.org.uk
7. Judák P, Esposito S, Coppieters G, Van Eenoo P, Deventer K. Doping control analysis of small peptides: A decade of progress. J Chromatogr B Analyt Technol Biomed Life Sci. 2021;1173:122551. PMID 33848801
8. Thevis M, Schänzer W. Analytical approaches for the detection of emerging drug candidates and non-approved drugs in human doping controls (title paraphrased). J Pharm Biomed Anal. 2014;101:66-83. PMID 24906629
9. Thomas A, Kohler M, Mester J, et al. Identification of the growth-hormone-releasing peptide-2 (GHRP-2) in a nutritional supplement. Drug Test Anal. 2010;2(3):144-148. PMID 20878896
10. Krug O, Thomas A, Walpurgis K, et al. Identification of black market products and potential doping agents in Germany 2010-2013. Eur J Clin Pharmacol. 2014;70(11):1303-1311. PMID 25168622
11. Fabresse N, Gheddar L, Kintz P, et al. Analysis of pharmaceutical products and dietary supplements seized from the black market among bodybuilders. Forensic Sci Int. 2021;322:110771. PMID 33838562
12. Coutinho LFD, de Oliveira Neves LF, et al. A new era of doping? Use of peptide and peptide-analog drugs in recreational and professional sport and bodybuilding: a critical review. J Sports Med Phys Fitness. 2026;66(7):880-885. PMID 41880199
13. García-Arnés JA, García-Casares N. Doping and sports endocrinology: growth hormone, IGF-1, insulin, and erythropoietin. Rev Clin Esp (Barc). 2023;223(3):181-187. PMID 36736729

This article is for laboratory research reference only. US Prime Peptides products are supplied strictly for in vitro research. Not for human consumption.

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