SS-31 — 50mg

SS-31 (also known as elamipretide, MTP-131, and Bendavia) is a cell-permeable tetrapeptide developed by Hazel Szeto at Cornell Medical College that selectively concentrates in mitochondria — reaching concentrations up to 1,000-fold higher in mitochondria than in cytoplasm. Its mechanism is distinct from conventional antioxidants: rather than scavenging free radicals after they form, SS-31 binds cardiolipin on the inner mitochondrial membrane and stabilizes the lipid environment required for proper electron transport chain (ETC) assembly and function. This structural preservation prevents the initial generation of reactive oxygen species rather than mopping them up downstream.

The compound's clinical trajectory under Stealth BioTherapeutics produced the first FDA approval of any mitochondria-targeted therapeutic: elamipretide was approved in 2024 as Forzinity for the treatment of Barth syndrome, a rare inherited cardiolipin-remodeling disorder. The approval followed a decade of clinical development spanning cardiovascular, ophthalmologic, and neuromuscular indications. Phase 3 trials in primary mitochondrial myopathy (MMPOWER-3), heart failure with preserved ejection fraction (HFpEF, EMBRACE), and dry age-related macular degeneration (ReCLAIM) produced mixed efficacy results but consistently validated the safety profile.

At the biological level, cardiolipin integrity is a fundamental determinant of mitochondrial function and is lost progressively with age — making SS-31 a natural candidate for aging research. Preclinical work has demonstrated restoration of mitochondrial ATP output in aged skeletal muscle, improved cardiac performance in models of diastolic dysfunction, and reduced oxidative damage across multiple tissues. The tetrapeptide's unusual mitochondrial tropism — driven by its alternating aromatic and basic residue sequence — has made it the prototype for a new class of compounds targeting subcellular organelles directly.