It is the most important of the melanocyte-stimulating hormones (MSHs) (also known as melanotropins) in stimulating melanogenesis, a process that in mammals (including humans) is responsible for pigmentation primarily of the hair and skin.

It also plays a role in feeding behavior, energy homeostasis, sexual activity, and protection against ischemia and reperfusion injury.

A few synthetic analogues of α-MSH have been investigated as medicinal drugs due to their photoprotective effects against ultraviolet (UV) radiation from the sun.

[3] Bremelanotide, another analogue of α-MSH, is available in the United States not as a photoprotective agent, but for the treatment of hypoactive sexual desire disorder in premenopausal women.

[4] All of these drugs have significantly greater potencies than α-MSH, along with improved pharmacokinetics and distinctive selectivity profiles.