Function
While Hexarelin is investigated for effects on GH secretion, cardiac protection, and muscle metabolism, with higher GH secretory potency than earlier GHRPs1929, SS-31 improves mitochondrial bioenergetics, reduces oxidative stress, and shows protective effects in models of ischemia-reperfusion, neurodegeneration, and other mitochondrial disorders4637137.
Mechanism
While Hexarelin works as a potent synthetic hexapeptide (examorelin) that agonizes GHSR-1a to stimulate GH release and also binds CD36, influencing cardiovascular and metabolic pathways19212996, SS-31 is a mitochondria-targeted tetrapeptide, d-Arg-dimethylTyr-Lys-Phe-NH2, that selectively binds cardiolipin in the inner mitochondrial membrane, stabilizing cristae structure, improving electron transport, and reducing ROS production4637137143.