Function
While Acetyl tetrapeptide-5 is used in cosmetic eye formulations to decrease puffiness, eye bags, and dark circles by reducing edema and protecting proteins such as SOD from glycation51150159154, SS-31 improves mitochondrial bioenergetics, reduces oxidative stress, and shows protective effects in models of ischemia-reperfusion, neurodegeneration, and other mitochondrial disorders4637137.
Mechanism
While Acetyl tetrapeptide-5 works as a synthetic tetrapeptide, Ac-βAla-His-Ser-His (Eyeseryl), with reported ACE-1 inhibition and anti-glycation activity, proposed to improve microcirculation and reduce capillary permeability and fluid accumulation in periorbital tissues51150159157, 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.