SS-31 (Elamipretide)

What Is SS-31 (Elamipretide)?

SS-31, known clinically as elamipretide, is a mitochondria-targeted aromatic-cationic tetrapeptide that concentrates on the inner mitochondrial membrane, where it binds cardiolipin and is proposed to help stabilise electron transport and ATP production. Unlike most peptides in this category, it has been through genuine human clinical trials, primarily for primary mitochondrial myopathy. It is an investigational drug developed by Stealth BioTherapeutics — not an approved dietary supplement or approved medicine.

Evidence

Elamipretide has real randomised human data, with a mixed record. An early phase 1/2 dose-escalation trial (MMPOWER) in adults with genetically confirmed primary mitochondrial myopathy reported improved distance on the 6-minute walk test and a well-tolerated profile ^{1Reference 1Karaa A et al. · 2018RCTRandomized dose-escalation trial of elamipretide in adults with primary mitochondrial myopathy — randomised RCTView study →}. However, the pivotal phase 3 trial (MMPOWER-3, N=218, 40 mg/day subcutaneously for 24 weeks) did not meet its primary endpoints — no significant difference from placebo on the 6-minute walk test or fatigue score — though the drug was again well tolerated, and post-hoc analysis suggested possible benefit in a genetic subgroup ^{2Reference 2Karaa A et al. · 2023RCTEfficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial — randomised RCTView study →}. So the honest summary is: mechanistically credible and clinically tested, but efficacy for its lead indication was not confirmed in phase 3. Consumer claims of general “anti-aging” or energy benefits go well beyond this trial evidence.

Dosage & Safety

The 40 mg/day subcutaneous dose above is the regimen used in MMPOWER-3 for a specific disease population under medical supervision — it is not a personal recommendation and does not imply a benefit outside that setting. Elamipretide is an investigational drug, not an approved dietary supplement; across trials it was generally well tolerated with mostly mild-to-moderate adverse events, most commonly injection-site reactions. Drug interactions and use in pregnancy were not assessed in this pass. This entry is informational only.

References

1. Karaa A, Haas R, Goldstein A, et al. (2018). Randomized dose-escalation trial of elamipretide in adults with primary mitochondrial myopathy — randomised RCT. Neurology. https://pubmed.ncbi.nlm.nih.gov/29500292/
2. Karaa A, Bertini E, Carelli V, et al. (2023). Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial — randomised RCT. Neurology. https://pubmed.ncbi.nlm.nih.gov/37268435/