Alpha-Melanocyte-stimulating hormone α-Melanocyte-stimulating hormone (alpha-MSH; α-MSH) also known as alpha-melanotropin alpha-melanocortin or alpha-intermedin is a naturally occurring endogenous peptide hormone of the melanocortin family with a tridecapeptide structure and the amino acid sequence Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2.