Melanocortin Research

Analogues of alpha-melanocyte-stimulating hormone, and the melanocortin receptors they are studied against. Melanotan I is the linear 13-amino-acid analogue; Melanotan II is shortened to seven residues and closed by a lactam bridge; PT-141 is a metabolite of Melanotan II in which the C-terminal amide is replaced by a hydroxyl group. The three are structurally related, and the differences between them are the reason they are studied side by side.