Longevity · 7 min read · Published September 8, 2026

SS-31 and Elamipretide: What the Forzinity Approval Does and Does Not Mean

Elamipretide (SS-31) became the first FDA-approved mitochondria-targeted peptide in September 2025, for one rare disease. What the approval covers, what the trials showed, and why it says nothing about the research-grade SS-31 sold online.

Is SS-31 FDA approved?

Elamipretide, the pharmaceutical form of SS-31, received FDA accelerated approval on September 19, 2025 as Forzinity for Barth syndrome, a rare mitochondrial disease, in patients over 30 kg. The approval rests on a muscle-strength endpoint and requires a confirmatory trial. It does not cover longevity, fatigue, or the research-grade 'SS-31' sold online.

Elamipretide is a good case study in how a real approval gets stretched by marketing. The molecule (D-Arg-dimethylTyr-Lys-Phe-NH2) was designed by Hazel Szeto and Peter Schiller in the early 2000s as one of a series of 'SS' peptides that concentrate in mitochondria. Stealth BioTherapeutics developed it as elamipretide. Our profile is at elamipretide.

How elamipretide works

Cardiolipin is a phospholipid found almost only in the inner mitochondrial membrane, where it holds the electron-transport complexes in their working shape. In disease and aging, cardiolipin becomes oxidized and the complexes lose efficiency, leaking electrons as reactive oxygen species. Elamipretide binds cardiolipin, restores the membrane's curvature and improves ATP production while reducing that leak (PMC9192202). It is not an antioxidant in the vitamin sense; it works on the structure that produces the oxidants.

Barth syndrome is caused by mutations in the TAZ gene that prevent cardiolipin from being remodeled correctly, so it is the purest test of the mechanism. That is why the approval came there first.

What the FDA approval covers

The FDA's announcement is here: FDA grants accelerated approval to first treatment for Barth syndrome. Accelerated approval means the agency accepted a surrogate or intermediate endpoint (here, muscle strength) on the condition that a further trial confirms clinical benefit; the approval can be withdrawn if it does not.

Why the gray-market SS-31 is not Forzinity

Forzinity is manufactured under GMP with verified identity, purity and sterility, prescribed for a specific disease, and monitored. Research-grade SS-31 vials have none of that: no regulator has checked what is in them, the July 2026 FDA review of similar products found certificates of analysis that did not match the labeled substance, and using them is not covered by any approval.

If you want to understand what a certificate of analysis can and cannot tell you, read our guide on how to read a peptide COA.

Should you take MOTS-c and SS-31 together?

No study has tested the combination, and neither peptide has a completed human efficacy trial outside elamipretide's rare-disease program. The 'SS-31 first, then MOTS-c' sequences shared online are opinions, not protocols from any trial. Both are mitochondria-related, which is the whole basis for pairing them.

For what MOTS-c has and has not shown, see MOTS-c: the mouse data and the one human trial.

Can SS-31 reverse aging?

In old mice, elamipretide improved mitochondrial function, heart performance and exercise capacity in short studies. No human trial has tested it in healthy older adults for any aging outcome, and the human trials that exist focus on rare diseases and eye disease. 'Reverses aging' is not a claim any published data supports.

What to watch

• The confirmatory Barth syndrome data required by the accelerated approval.
• ReNEW Phase 3 results in dry AMD, which would be the first common-disease indication.
• Whether the FDA's 2026 compounding reviews ever extend to elamipretide (they have not; it was not on the July 2026 agenda).