MOTS-c, SS-31 (elamipretide) and Humanin are peptides that act on the mitochondria, the parts of each cell that make energy. MOTS-c is studied for metabolism and exercise capacity, SS-31 for protecting the inner mitochondrial membrane, and Humanin for cell protection with age. SS-31 has the most human data and a US approval for one rare disease. MOTS-c and Humanin are still mostly studied in animals. None is a proven anti-ageing treatment, so a physician should decide whether one fits you.