Elamipretide (SS-31)

Elamipretide is a mitochondria-targeted tetrapeptide. The former research name was SS-31. The brand name is Forzinity.

Elamipretide binds and stabilizes cardiolipin in the inner mitochondrial membrane. That action improves mitochondrial function and decreases toxic reactive oxygen species.

Evidence tier: clinical.

The Phase 3 TAZPOWER trial (NCT03098797) and an Expanded Access Program studied Barth syndrome. Both showed an improvement in muscle strength and in quality of life.

Preclinical work shows a benefit in cardiac ischemia models and in aged-muscle models.

Source: the FDA label.

The label covers an improvement in muscle strength in adults and children with Barth syndrome who weigh at least 30 kg. The route is subcutaneous injection.

A prescriber controls the schedule.

The route is subcutaneous. The molecule crosses the blood-brain barrier only a little.

The label does not document interactions in detail.

Compare with Humanin and MOTS-c.

Trials reported injection site reactions.

The trials used muscle-strength endpoints. Examples are knee extensor strength and the 6-minute walk test.

The FDA granted accelerated approval on 19 September 2025. The product is FORZINITY, NDA 215244, from Stealth BioTherapeutics. It is the first FDA-approved mitochondria-targeted therapeutic.

The approval changes the WADA position. Before it, the compound fell under the non-approved substance rule.

See the FDA-approved peptides list.