A mitochondria-targeting tetrapeptide (elamipretide) that binds cardiolipin in the inner mitochondrial membrane, studied across several trials with mixed results.
Reviewed for accuracy · Last reviewed July 7, 2026SS-31, known as elamipretide, is a synthetic tetrapeptide that targets mitochondria: it binds cardiolipin in the inner mitochondrial membrane, helps stabilize the membrane's structure, and is studied for improving mitochondrial function. Unlike most research peptides, it has been through a substantial clinical program, including trials in mitochondrial myopathy, heart failure, and eye disease.
The evidence is genuinely mixed. In September 2025 it received FDA accelerated approval as FORZINITY for the ultra-rare Barth syndrome, based on a muscle-strength endpoint, with confirmatory trials still required. But its larger MMPOWER-3 trial in primary mitochondrial myopathy did not meet its primary endpoints. So it is narrowly and conditionally approved for one rare disease, not a broadly proven compound, and other uses are off-label or investigational.
The approved Barth syndrome product (FORZINITY) and the mitochondrial myopathy trials used 40 mg subcutaneously once daily. Research use outside that narrow indication has no established dose.
Read the full SS-31 dosage guide →In its clinical program the most consistent reactions were injection-site reactions. Because approval is narrow and recent, its adverse-effect profile outside the studied populations is not well characterized.
Read the full SS-31 side effects guide →The approved product has its own storage instructions. For research vials, keep the unmixed peptide refrigerated and away from light, and store any reconstituted solution refrigerated. See the full storage & safety guide for handling and disposal basics.
This page is an independent educational reference and is not medical advice. Talk to a doctor before starting any compound.