Where research peptides sit on the WADA Prohibited List

Most research peptides fall into two sections of the World Anti-Doping Agency's 2026 Prohibited List: S0, the catch-all for substances no health authority has approved, and S2, peptide hormones and growth factors. TB-500 is named in S2.3; the GHRH analogues, secretagogues and GHRPs, including CJC-1295, sermorelin and ipamorelin, in S2.2.4; BPC-157 is the named S0 example. All of these are prohibited in and out of competition, and a peptide the List does not name, such as Melanotan II, is not thereby permitted.

What the Prohibited List is, and who it binds

The Prohibited List is the international standard, issued under the World Anti-Doping Code, that identifies the substances and methods banned in sport. WADA updates it annually and the new List takes effect on January 1 of each year; the 2026 edition was approved by WADA's Executive Committee in September 2025. It binds athletes who compete under the Code, which in the United States means the sports whose anti-doping programs USADA runs, and it is enforced through testing rather than through any product regulator.

FDA regulates what may be sold as a drug in the United States. WADA governs what an athlete may have in their body. A substance's answer to one question says nothing about its answer to the other.

What "prohibited at all times" and "Specified" mean

The List sorts substances two ways. The first is timing: some classes are prohibited only in competition. The classes that matter here, S0 and S2, are marked "PROHIBITED AT ALL TIMES (IN- AND OUT-OF-COMPETITION)," so a finding is a violation whenever the sample was taken.

The second is the Specified and non-Specified distinction, which affects how a violation is sanctioned rather than whether it is one. The 2026 List states that all S0 substances are Specified Substances and all S2 substances are non-Specified. Both are violations. The label changes what a tribunal may consider afterward; it does not make either class less prohibited.

Strict liability

Anti-doping runs on strict liability. USADA's summary is that "an athlete is responsible for any prohibited substance found in their body, regardless of intent." It is not necessary to show that the athlete meant to use it, knew it was there, or was careless. Presence is the violation.

A vial labelled "research use only" is exactly as prohibited as anything else if its contents are in the List's classes. The label is no defence in sport, as it is none under drug law. Nothing on this site is supplied for use in a person, and this page is a classification reference, not a guide to what an athlete may take.

What S0 is

S0 is the List's catch-all for substances that no regulator has approved. In our words, the 2026 text covers any pharmacological substance that no later section of the List addresses and that no government regulator has approved, and gives as examples drugs still in development or discontinued, designer drugs and substances approved only for veterinary use. It is prohibited at all times. The substances it names include BPC-157, 2,4-dinitrophenol (DNP), ryanodine receptor-1-calstabin complex stabilizers and troponin activators.

Two features of S0 are easy to miss. First, it is defined by approval status, not by chemistry or effect, so a compound falls into it simply by having no approval anywhere and not fitting a later section. Second, it names BPC-157 only as an example. A research peptide with no approval by any health authority is in S0 whether or not WADA has ever written its name down. USADA's own page on BPC-157 states that it "is prohibited under the S0 Non-Approved Substances category of the List" and "is not approved for human clinical use by the U.S. Food and Drug Administration (FDA) or any other global health authority."

What S2 is

S2 is "Peptide hormones, growth factors, related substances, and mimetics." Its opening sentence is the other catch-all worth reading: "The following substances, and other substances with similar chemical structure or similar biological effect(s), are prohibited." The named examples are then grouped under the hormone or growth-factor system WADA files them beneath.

Section S2.2.4 covers growth hormone releasing factors. In our words, it names GHRH and its analogues, with CJC-1293, CJC-1295 and sermorelin among the examples; growth hormone secretagogues and their mimetics, among them anamorelin, capromorelin, ibutamoren (MK-677), ipamorelin, lenomorelin (ghrelin), macimorelin and tabimorelin; and GH-releasing peptides (GHRPs), among them alexamorelin, examorelin (hexarelin) and GHRP-1 to GHRP-6, with GHRP-2 also listed as pralmorelin. The wording is in section S2.2.4 of the 2026 List.

S2.2.4 has three sub-groups: GHRH analogues, growth hormone secretagogues and GHRPs. Ipamorelin is placed among the secretagogues, not the GHRPs, which answers "is ipamorelin a GHRP" in WADA's own terms.

The growth factors sit in S2.3, which includes "Thymosin-ß4 and its derivatives e.g. TB-500." Growth hormone fragments are S2.2.3, with "AOD-9604 and hGH 176-191" as the examples. Kisspeptin is in S2.2.1, alongside gonadorelin and its agonist analogues.

Where the research peptides sit

The table gives each molecule's placement in the 2026 List, as of September 21, 2026. Every named section in it is prohibited at all times. "Not named" means the name does not appear in the List's text or index; it does not mean the substance is permitted, because S0 and the "similar biological effect(s)" clause of S2 are catch-alls. The US column lets the two statuses be read side by side; the full FDA picture is in the FDA status table.

The "not named" rows are where the two catch-alls do their work. Melanotan II has no approval from any health authority, which is the S0 definition, even though the List does not print its name. The unnamed peptides in the last row are in the same position. Absence from the examples is not a clearance, and WADA's summary of major modifications for 2026 records, for the substance classes, further examples and clarifications to S1, S2, S4 and S6, not any narrowing.

FDA status and WADA status: the four combinations

Because the two systems ask different questions, every combination occurs.

• Approved by FDA, prohibited by WADA. Sermorelin: Geref was approved in 1997 and later discontinued, and sermorelin is a named S2.2.4 example.
• Not approved by FDA, prohibited by WADA. BPC-157, TB-500, CJC-1295, ipamorelin.
• Approved by FDA, not named by WADA. Bremelanotide.
• Not approved by FDA, not named by WADA. Melanotan II, Semax, Selank, KPV. These fall to the S0 definition, not to a listed name.

"Legal" and "permitted in sport" are unrelated. An approved product can be lawful to sell and still get an athlete sanctioned. A research vial of CJC-1295 has no approval of any kind and is also a named S2.2.4 substance.

What about the NCAA?

The NCAA maintains its own banned-drug classes rather than adopting WADA's List by reference. Its banned-substances page names eight classes, including "Peptide hormones, growth factors, related substances and mimetics," and states that "any substance chemically/pharmacologically related to these classes is also banned" and that "the school and the student-athlete shall be held accountable for all substances within the banned-drug class regardless of whether they have been specifically identified." The NCAA's page is explicit that "THERE IS NO COMPLETE LIST OF BANNED SUBSTANCES." The peptide class is defined the same way WADA's S2 is, by kinship rather than by an exhaustive list, so a collegiate athlete's question has the same shape as a Code athlete's.

Common questions

Is TB-500 on the WADA Prohibited List?

Yes. The 2026 Prohibited List names it in section S2.3, which includes Thymosin-ß4 and its derivatives e.g. TB-500. S2 is prohibited at all times, in and out of competition, and all S2 substances are non-Specified, a label that affects how a violation is sanctioned and not whether it is one.

What is the S0 category on the WADA Prohibited List?

It is the List's catch-all for substances that no regulator has approved. S0 is defined by approval status, not by chemistry or effect, so a compound falls into it by having no approval from any government regulator and not fitting a later section. The 2026 text names BPC-157 only as an example.

If a peptide is not named on the WADA list, is it permitted in sport?

No. Not named means the name does not appear in the List's text or index, not that the substance is permitted, because S0 and the similar biological effect(s) clause of S2 are catch-alls. Melanotan II has no approval from any health authority, which is the S0 definition, even though the List does not print its name.

Does FDA approval mean a peptide is permitted by WADA?

No. FDA regulates what may be sold as a drug in the United States, and WADA governs what an athlete may have in their body. Sermorelin shows the gap: its FDA-approved product, Geref, was approved in 1997 and later discontinued, and sermorelin is a named S2.2.4 example on the 2026 Prohibited List.

Sources

• The 2026 Prohibited List (PDF), World Anti-Doping Agency, valid January 1, 2026
• WADA's 2026 Prohibited List is now in force, World Anti-Doping Agency, January 1, 2026
• The Prohibited List, World Anti-Doping Agency
• BPC-157: Experimental Peptide Creates Risk for Athletes, USADA
• Anti-Doping 101, USADA
• WADA Prohibited List, USADA
• NCAA Banned Substances, NCAA, current
• Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks, FDA, content current April 22, 2026