Melanocortin

Melanocortins are a group of pituitary peptide hormones that include adrenocorticotropin (ACTH) and the alpha, beta and gamma melanocyte-stimulating hormones (MSH) that derive from the prohormone proopiomelanocortin.

Melanocortins act through a multitude of melanocortin receptors designated MC1 through MC5. MC2 is also known as the adrenocorticotrophic hormone receptor since it selectively binds ACTH. The other melanocortin receptors are semi-selective in their ability to bind multiple melanocortins to some degree.

Pharmacology
Several synthetic melanocortins are in development including Clinuvel's CUV1647 (Melanotan) for sunless tanning and Palatin Technologies' bremelanotide for erectile dysfunction and sexual arousal disorder.