The WADA Prohibited List 2026 has been in force since 1 January 2026. For research peptides, class S0 is the decisive one: it prohibits any pharmacological substance without marketing authorisation, even where the substance itself is nowhere mentioned by name.
- At all times: S0 to S5 and methods M1 to M3 apply both in and out of competition.
- S0 is a catch-all: no approval from a medicines authority means prohibited — BPC-157 is the best-known example.
- Monitored, not prohibited: semaglutide and tirzepatide are on the Monitoring Program 2026, not on the Prohibited List.
- New in 2026: method M1.4 prohibits the non-diagnostic use of carbon monoxide.
What is this about?
Almost every research peptide you will come across in this knowledge base is prohibited for athletes. Not because every peptide is named on the WADA Prohibited List, but because class S0 is a catch-all: any pharmacological substance without human medicinal product approval falls under it. Substances that are only for sale as research chemicals by definition do not have that approval. This page explains which classes of the Prohibited List 2026 affect peptides, where the exceptions lie, and how to check a substance yourself.
The Prohibited List 2026 at a glance
The WADA Prohibited List is an international standard under the World Anti-Doping Code. The 2026 version has been in force since 1 January 2026 and is revised annually. The list has two blocks. The first block applies at all times, and therefore also out of competition and during the training period: substance classes S0 to S5 and methods M1 to M3. The second block applies during competition only: S6 to S9 and P1.
Every class that affects peptides, peptide hormones and growth factors sits in the first block. So for peptides the rule is this: prohibited means prohibited all year round, including during preparation.
S0: the catch-all class that affects most research peptides
Class S0 covers any pharmacological substance that is not mentioned elsewhere on the list and that is not currently approved by any government authority for human therapeutic use. Think of substances in preclinical research, substances in ongoing clinical trials, and substances whose development has been discontinued. WADA itself cites BPC-157 as an example under S0.
Two consequences are often missed. First: “not named on the list” does not mean “not prohibited”. Where the approval is absent, S0 applies, even without a specific mention. Second, it also works the other way round: a marketing authorisation in a single country is enough for S0 not to apply. Elamipretide (SS-31) received a marketing authorisation in the United States in 2025 and therefore no longer falls under S0. Statuses of this kind can thus shift from year to year.
What does “at all times” mean? That the substance is also prohibited out of competition: during preparation, during a training period and out of season. Only classes S6 to S9 and P1 apply in competition only.
The classes that affect research peptides
The table below summarises the classes that research peptides fall under in practice. All the classes listed apply at all times: there is no distinction between in and out of competition.
| Class | What the class covers | Examples from this category |
|---|---|---|
| S0 | Non-approved substances — the catch-all | BPC-157 |
| S1.2 | Other anabolic agents, including SARMs | enobosarm (ostarine), LGD-4033, RAD140, YK-11, S-23, clenbuterol |
| S2.1 | Erythropoietins and agents affecting erythropoiesis | EPO, CERA, roxadustat, luspatercept, asialo-EPO, carbamylated EPO |
| S2.2.1 | Testosterone-stimulating peptides, in males | hCG, LH, gonadorelin (GnRH), kisspeptin |
| S2.2.2 | Corticotrophins and their releasing factors | corticorelin, tetracosactide |
| S2.2.3 | Growth hormone, analogues and fragments | growth hormone, somapacitan, somatrogon, AOD-9604, hGH 176-191 |
| S2.2.4 | Growth hormone releasing factors | CJC-1293, CJC-1295, sermorelin, tesamorelin, ipamorelin, hexarelin (examorelin), GHRP-1 to GHRP-6, ibutamoren (MK-677), anamorelin |
| S2.3 | Growth factors and growth factor modulators | IGF-1 (mecasermin), mechano growth factors, thymosin β-4 (TB-500), VEGF, PDGF, FGF, HGF |
| S4.1 | Aromatase inhibitors | anastrozole, letrozole, exemestane, formestane |
| S4.2 | Anti-oestrogenic substances | clomifene, tamoxifen, raloxifene, toremifene |
| S4.3 | Agents preventing activin receptor IIB activation | follistatin, myostatin propeptide, ACE-031, bimagrumab, apitegromab |
| S4.4 | Metabolic modulators | AICAR, MOTS-c, BAM15, GW1516 (GW501516), SR9009, insulins and insulin mimetics, meldonium, trimetazidine |
| S5 | Diuretics and masking agents | desmopressin, probenecid, hydrochlorothiazide, spironolactone |
GLP-1 agonists: monitored, not prohibited
Semaglutide and tirzepatide are not on the Prohibited List 2026. They have been on the WADA Monitoring Program since 2024: WADA collects anonymised data on their use, in and out of competition, in order to build a picture of patterns of misuse. A substance on the Monitoring Program is therefore not prohibited — but the Prohibited List is revised annually, and the Monitoring Program is usually the waiting room.
Note the difference with the newer incretin peptides. Retatrutide, cagrilintide and survodutide hold no marketing authorisation anywhere. They are not named on the Prohibited List, but that is precisely why they do fall under S0. Liraglutide, by contrast, is approved and is not on the list.
What has changed in the 2026 version?
For 2026, WADA points mainly to clarifications. The wording has been tightened for S1 (anabolic agents), S2 (peptide hormones and growth factors), S4 (hormone and metabolic modulators) and S6 (stimulants), so that athletes and their support personnel can see more easily what falls under each. In addition, the non-diagnostic use of carbon monoxide has been added as a new prohibited method, M1.4, and cell components have been added to the existing prohibition on the use of cells. The dosing interval for salmeterol has also been amended, and the wash-out periods for glucocorticoids have been clarified.
Monitoring is not a prohibition. WADA tracks the pattern of use of a monitored substance in order to assess whether it should be added to the list in a future edition. A finding does not in itself constitute a violation.
Five misconceptions that come up often
- Not on the list means not prohibited. Incorrect: S0 catches every unapproved pharmacological substance, even without a specific mention.
- TB-500 and thymosin alpha-1 are the same thing. Incorrect: thymosin β-4 (TB-500) is named in S2.3. Thymosin alpha-1 is not on the list and holds a marketing authorisation in several countries.
- Melanotan is a single substance. Incorrect: afamelanotide (melanotan I) is approved; melanotan II is not, and therefore falls under S0.
- A fragment does not count. Incorrect: a fragment of an unapproved substance is itself unapproved. And hGH 176-191 and AOD-9604 are, moreover, named in S2.2.3.
- Only competitive athletes need to pay attention. Incorrect: the peptide classes are prohibited at all times, and therefore also out of season and out of competition.
How do you check a substance yourself?
Three sources, in this order. First, the Prohibited List itself, published by WADA. Second, Global DRO, which looks up brand names and routes of administration — bear in mind that Global DRO covers approved medicines and not research chemicals. Third, your national anti-doping organisation, in the Netherlands the Dopingautoriteit, for binding advice and for a TUE. A TUE (therapeutic use exemption) must be applied for before use, with medical justification.
What this means for research at Peplife
Peplife supplies for laboratory research only (Research Use Only). The products are not intended for use in humans or animals, and therefore not for sport either. Every product page states the WADA status of the substance concerned, together with the class that applies to it. That information is indicative: the Prohibited List itself and your anti-doping organisation are authoritative.
Last checked against the WADA Prohibited List 2026 (in force 1 January 2026) and the WADA Monitoring Program 2026.
Related research · RUO
- Buying peptides in Europe: RUO, legislation and what to look out for — the legal framework alongside the anti-doping rules
- BPC-157 research — the best-known S0 example, in plain language
- TB-500 research: thymosin beta-4 — the substance behind class S2.3
- Retatrutide vs Tirzepatide vs Semaglutide — why one is monitored and the other is not
- Growth hormone peptides: an overview of the GH axis — the class with the most entries
- The FDA and peptides: what is really going on (2026) — why marketing authorisation is the pivotal point
Frequently asked questions
Is BPC-157 on the WADA Prohibited List?
Yes. BPC-157 is named in the Prohibited List 2026 as an example under S0, the class for non-approved substances. The reason is that nowhere in the world is there an approval from a medicines authority for therapeutic use in humans. S0 applies at all times, and therefore also out of competition.
Is semaglutide or tirzepatide doping?
No. Both have been on the WADA Monitoring Program since 2024 and are not on the Prohibited List 2026. Newer substances from the same family that do not yet hold a marketing authorisation — such as retatrutide, cagrilintide and survodutide — do fall under S0, precisely because that authorisation is absent.
Is TB-500 (thymosin beta-4) prohibited?
Yes, under S2.3: growth factors and growth factor modulators. Note the difference with thymosin alpha-1, which is not named on the 2026 list.
Does a prohibition also apply out of competition?
For every class that affects research peptides: yes. S0 to S5 and methods M1 to M3 apply at all times. Only classes S6 to S9 and P1 are restricted to competition.
What if a substance is not on the list?
It is then not automatically permitted. S0 works as a catch-all: any pharmacological substance that falls into no other class and that has no approval from a medicines authority for therapeutic use in humans is prohibited. Most research peptides fall into exactly that category.
Can an athlete obtain a TUE (therapeutic use exemption)?
For a substance without any marketing authorisation this is in practice virtually impossible, because a TUE requires a medical indication and a recognised treatment plan. An application always goes through the national anti-doping organisation or the international federation.
Disclaimer
This article discusses scientific research and is informational only. The compounds mentioned are supplied by Peplife strictly as Research Use Only (RUO) for laboratory research. Nothing here is medical, diagnostic, or dosing advice. Named medicines are cited only to discuss published research.