SS-31

SS-31 (elamipretide, also designated MTP-131) is a synthetic, cell-permeable tetrapeptide with an alternating aromatic–cationic structure (D-Arg-2′,6′-dimethyltyrosine-Lys-Phe-NH₂). It belongs to the Szeto-Schiller family of mitochondria-targeted peptides and is one of the most extensively characterised compounds in mitochondrial medicine research.

Mechanism

SS-31 concentrates selectively in the inner mitochondrial membrane, where it binds cardiolipin — the signature phospholipid that organises the membrane's cristae architecture and anchors the electron transport chain. By stabilising cardiolipin, SS-31 restores proper cristae curvature, improves the coupling efficiency of oxidative phosphorylation, and reduces the electron leakage that generates reactive oxygen species. Importantly, it is not an antioxidant that scavenges free radicals after the fact; it addresses the structural cause of their overproduction.

What the research shows

• Increased ATP output and improved respiratory efficiency in energy-demanding tissue
• Substantial reduction in mitochondrial reactive oxygen species and oxidative damage markers
• Restoration of muscle function and fatigue resistance in models of age-related mitochondrial decline
• Preservation of cardiac and renal tissue in ischaemia-reperfusion injury models
• Protection of cristae structure in models of primary mitochondrial myopathy

Because mitochondrial efficiency underlies endurance, recovery and cellular longevity, SS-31 has become a reference compound in bioenergetics research.