Melanotan II is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (alpha-MSH) that acts as a non-selective melanocortin receptor agonist. The peptide stimulates melanogenesis through MC1 receptor activation, increasing eumelanin production in melanocytes. Melanotan II was among the peptides removed from FDA Category 2 restriction in April 2026. Research applications include melanocortin receptor studies, pigmentation pathway research, and photoprotection mechanisms. The peptide is supplied as a lyophilized powder and has been a target of FDA enforcement actions due to widespread unauthorized marketing with cosmetic claims.
Directory listing last reviewed July 2026.