Regulatory Changes Impacting Peptide Use in Sports

What this timeline covers

Most of the rules that touch MOTS-c and SS-31 in sport have changed since 2022, and several changed within the last year. This page lists those changes in date order and explains what each one did. For where things stand today, body by body, see the current regulatory picture for mitochondrial peptides in sport. For how WADA testing and sanctions work, see how the WADA rules apply to MOTS-c and SS-31.

Two bodies matter most. WADA's Prohibited List, revised every year, decides what a tested athlete can't use. The US FDA decides what can be sold or compounded as a drug, which shapes where peptides come from. The two mostly run separately: a compounding decision at FDA doesn't change anything on the WADA list. SS-31 is the exception, because WADA's S0 rule depends on whether a drug is approved anywhere.

WADA list changes

2022: BPC-157 becomes the first named S0 example

S0 ("non-approved substances") works as a catch-all. It bans, at all times, any pharmacological substance that no later section of the list covers and that has no current approval from any government health regulator for human therapeutic use. Until 2022 it named no examples. The 2022 List added BPC-157 "following a recent re-evaluation," and WADA said it was the first substance ever included by name in S0, describing it as an experimental peptide sold as a supplement. USADA's advisory on the 2022 List said BPC-157 was not prohibited before then.

2025: MOTS-c named under S4.4.1

MOTS-c was first described in a 2015 mouse study as a mitochondria-encoded peptide that improved insulin resistance and limited diet-induced obesity. For about a decade it wasn't named on the list, so its sport status rested on how you read the general wording. The earlier version of this page filed it under S0.

The 2025 List, approved on 12 September 2024 and in force from 1 January 2025, settled it. WADA added MOTS-c ("mitochondrial open reading frame of the 12S rRNA-c") as an example of an AMPK activator in S4.4.1, next to AICAR. S0 only covers substances that no other section addresses, so once MOTS-c was named as an AMPK activator, S4.4.1 is the section that applies.

The section matters for sanctions. Everything in S0 is a Specified Substance, while S4.4 substances are non-Specified, which generally means a harsher starting point if an athlete tests positive. The testing and sanctions page linked above explains the difference. The peptide's own evidence base is covered in our MOTS-c overview.

2026: MOTS-c unchanged, BAM15 added beside it

The 2026 List has been in force since 1 January 2026. It keeps MOTS-c in S4.4.1 as a non-Specified substance and adds BAM15, a synthetic compound WADA says has been found in supplements, to the same AMPK activator entry. It also extended M3 (gene and cell doping) to cover cell components, "e.g. nuclei and organelles such as mitochondria and ribosomes." That M3 change concerns transferring mitochondria themselves; it doesn't affect MOTS-c or SS-31.

As of October 2026, the 2026 List also places the peptides most often discussed alongside these two. BPC-157 is in S0 and TB-500 is in S2.3. GH fragments, including AOD-9604, are in S2.2.3, and GHRH analogues and GH secretagogues are in S2.2.4. IGF-1 and its analogues are in S2.3. Each of these is named or covered by a named class, so none of them is "pending classification."

2027: "peptides" written into S0

WADA published the 2027 List on 21 September 2026, and it takes effect on 1 January 2027. The S0 definition now gives these examples: "drugs under pre-clinical or clinical development or discontinued, designer drugs, peptides, substances approved only for veterinary use." WADA's explanatory note says many unapproved peptides already met the criteria for S0 "or other classes (such as S2 or S4)," and that "for clarity, peptides are now named as examples in this section."

So the 2027 change is a clarification rather than a new ban. Two details matter for this topic. MOTS-c stays in S4.4.1 in the 2027 text, so the new S0 wording doesn't move it. And S0's approval test is unchanged, so the new word doesn't settle SS-31's case either. USADA's advisory on the 2027 List describes a "peptide craze" that "may pose serious anti-doping and health risks."

SS-31: approval changed the question (September 2025)

On 19 September 2025, the FDA granted accelerated approval to Forzinity (elamipretide, the compound research-peptide shops sell as SS-31) as the first treatment for Barth syndrome, in patients weighing at least 30 kg. The approval rests on improved strength in the muscle that straightens the knee, and FDA requires a confirmatory randomized, placebo-controlled trial. Forzinity is a prescription medicine. Vials sold as "research use only" SS-31 aren't the approved product.

Before approval, SS-31 fit S0's wording as an unapproved drug in clinical development, which is why the earlier version of this page listed it under S0. Since September 2025 it has a current approval from a government health regulator, so S0 no longer clearly applies. Neither the 2026 nor the 2027 List names elamipretide. Whether WADA treats it under another section, such as the S4.4 metabolic modulators, is something we couldn't confirm: as of October 2026 we found no WADA or USADA statement on it. Its status is unverified, which is not the same as permitted. USADA points athletes to GlobalDRO and its Drug Reference Line for substances the list doesn't name.

The ethics of an athlete using a prescription drug outside its approved use, and the US law around it, are covered in our page on ethics and US law for athletes.

FDA compounding changes, 2023 to 2026

This history shaped where US users got MOTS-c. SS-31 sits mostly outside it, since it wasn't among the peptides FDA placed in Category 2 in 2023.

• September 2023. FDA added 19 peptides, including MOTS-c and BPC-157, to Category 2 of its 503A bulk substances list, the category for substances it says may present significant safety risks in compounding. For MOTS-c, FDA wrote that it had "not identified any human exposure data" by any route. According to a law-firm summary (Orrick), Category 2 status became the basis for FDA enforcement against compounders who kept using these peptides.
• October and December 2024. Some nominators withdrew their nominations, and FDA brought several peptides to its Pharmacy Compounding Advisory Committee (PCAC) anyway. The committee voted 0-12 against ipamorelin (for each salt form) on 29 October 2024 and voted against every form of CJC-1295 on 4 December 2024 (0-13 or 1-12). MOTS-c wasn't on either agenda.
• April 2026. HHS Secretary Robert F. Kennedy Jr. said in February that the administration wanted peptides to be more accessible. On 15 April FDA announced it would remove 12 peptides, including MOTS-c and BPC-157, from Category 2 because their nominations had been withdrawn; removal took effect about a week later. Removal doesn't permit compounding: these peptides now sit in no category.
• July 2026. On 23 July the PCAC voted 7-5, with 2 abstentions, to recommend MOTS-c (reviewed for obesity and osteoporosis) for the 503A list, and 8-6 with 1 abstention for BPC-157 (reviewed for ulcerative colitis). FDA's own scientists had recommended against both. As of October 2026, FDA hasn't proposed a rule, and the 503A list still names no peptide. A second PCAC meeting on other peptides is planned before the end of February 2027.

None of this changes the sport rules. A MOTS-c product from a compounding pharmacy would still be an S4.4.1 substance for a tested athlete.

Enforcement against research-peptide sellers (2026)

FDA's 24 August 2026 warning letter to Tex Peptides (TXP Innovations) lists "SS-31 (Elamipretide)" among products it calls unapproved new drugs, next to several GLP-1 products. The letter says the site's "research use only" and "not for human or veterinary use" labels didn't change that, because its product descriptions and its sale of bacteriostatic water showed the products were meant for injection in people. In other words, the active ingredient of an approved drug, sold outside that approval, is still treated as an unapproved drug.

Health Canada made the same point on 9 April 2026. Its public advisory lists MOTS-C and SS-31 among unauthorized injectable peptides it has seized and says research-use labeling "does not make these products legal or exempt from regulatory requirements."

For athletes, the main retail channel for both peptides is now under direct regulatory pressure in the US and Canada, and product quality in it is still unregulated.

What to watch next

• Whether FDA proposes a rule after the July 2026 PCAC votes, and what the February 2027 meeting decides about the remaining peptides.
• Whether WADA or USADA says how elamipretide is treated now that it's approved, and how its confirmatory trial turns out.
• The 2028 List, due around September 2027, for any newly named peptides.