Is SS-31 legal?

What that status actually means.

SS-31 is in registered human clinical trials but has not been approved. Investigational status means a regulator has permitted the compound to be studied in humans under a controlled protocol, which is a meaningful step, and specifically not a finding that it is safe or effective.

Material sold commercially is not trial material. Compounds in clinical development are supplied to trial sites under controlled conditions, so anything available to buy is a separate product of unverified identity and purity that happens to share a name.

Investigational compounds fail regularly, including at late stages and including after promising early results. A drug in Phase 3 has not yet cleared the bar that most candidates do not clear.

The regulatory record for SS-31.

As elamipretide HCl (FORZINITY), SS-31 received FDA accelerated approval in September 2025 for Barth syndrome, making it the first approved mitochondria-targeted peptide; accelerated approval means continued approval may depend on confirmatory benefit. For all other uses (e.g., heart failure, mitochondrial myopathy, ophthalmic and "anti-aging" applications) it remains investigational or unproven, and material marketed as "SS-31" for research is not an FDA-approved drug for those purposes.

Compounding, sport, and jurisdiction.

Three separate regimes govern a compound like this one, and they move independently. US compounding eligibility runs through sections 503A and 503B and the FDA lists that sit under them, which are revised over time as the agency evaluates individual substances. A compound can be widely compounded one year and removed from eligibility the next.

Anti-doping status is set separately by WADA and does not track FDA approval at all. The prohibited list covers peptide hormones, growth factors, related substances and mimetics as categories, which means an unapproved research compound can be firmly prohibited in competition while an approved medicine is permitted with the right documentation.

And none of this is global. Approval, scheduling and import rules differ by country, and a compound registered as a medicine in one jurisdiction can be entirely unapproved in another. Several compounds on this site are prescription medicines in one country and research chemicals in the next.