SS-31 (Elamipretide)

Mitochondria-targeted peptide that binds cardiolipin and rescues inner-membrane function.

Where MOTS-C signals the mitochondria, SS-31 physically goes inside them. It binds cardiolipin, a fat that holds the inner membrane's energy-producing machinery in the right shape; in aged or damaged cells that machinery turns sloppy and leaky, and SS-31 restores it. The payoff is more efficient energy production with less oxidative "exhaust" — which is why it's been studied for heart failure, mitochondrial muscle disease, and the age-related decline in muscle power. It's a repair tool for tired cellular engines.