SS-31 (Elamipretide)

SS-31, also known by its non-proprietary name Elamipretide, is a synthetic, water-soluble tetrapeptide. It is a prominent member of the Szeto-Schiller (SS) class of peptides, which are uniquely characterized by their ability to selectively target and accumulate within mitochondria.

Its primary mechanism of action involves crossing the cell membrane and localizing to the inner mitochondrial membrane, a process that occurs independent of mitochondrial membrane potential. There, it associates with cardiolipin, a phospholipid that is critical for maintaining the structural integrity and function of the electron transport chain complexes responsible for ATP synthesis. By binding to cardiolipin, SS-31 is thought to protect it from peroxidation by reactive oxygen species (ROS), thereby preserving mitochondrial function, improving cellular energy production, and reducing oxidative stress at its source.

Because mitochondrial dysfunction is a key pathological driver in many conditions, Elamipretide is being investigated as a potential therapeutic for a wide array of diseases. As of June 2025, it has been the subject of numerous clinical trials for cardiovascular, neurodegenerative, and rare mitochondrial diseases, and remains an investigational drug under active development.