SS-31

A synthetic tetrapeptide (D-Arg-2',6'-Dmt-Lys-Phe-NH2) with a unique ability to selectively concentrate in the inner mitochondrial membrane by binding cardiolipin — a phospholipid critical for electron transport chain organisation and function. By stabilising cardiolipin, SS-31 restores the structural integrity of the mitochondrial cristae (the folded inner membrane where ATP synthesis occurs), dramatically improving electron transport chain efficiency. This reduces reactive oxygen species (ROS) leakage, increases ATP production, and protects against the mitochondrial dysfunction that underlies cellular ageing, cardiac stress, and exercise fatigue. SS-31 is the most precisely targeted mitochondrial therapeutic ever developed — while NMN and NAD+ precursors raise substrate availability, SS-31 improves the machinery itself.

Developed by Hazel Szeto at Weill Cornell Medicine. FDA-approved as Elamipretide (Stealth BioTherapeutics) for Barth syndrome — a rare mitochondrial cardiomyopathy — in 2022, making it the first FDA-approved mitochondria-targeted peptide therapeutic. In healthy ageing research, SS-31 has shown remarkable results: a 2020 study demonstrated that a 2-hour SS-31 infusion in humans acutely improved mitochondrial ATP production in skeletal muscle by 36%. Animal studies show improved cardiac function, restored exercise capacity in aged animals, and reversal of multiple age-related metabolic defects. Growing interest in longevity medicine as evidence accumulates that mitochondrial dysfunction is a primary driver of the ageing phenotype rather than a consequence of it.

12–24 week courses for longevity applications