What it is

SS-31 is a mitochondria-targeted peptide: D-Arg, dimethyltyrosine, Lys and Phe, with a capped end. Its alternating positive and ring-shaped links let it cross cell membranes and gather about 1,000-fold in the inner mitochondrial membrane. There it binds cardiolipin, the fat that holds the energy-making complexes in place. Cells make more ATP and leak fewer free radicals. It is sold as elamipretide, brand FORZINITY, at 40 mg a day for Barth syndrome.