[Nle4,D-Phe7]-α-MSH (trifluoroacetate salt)

[Nle4,D-Phe7]-α-MSH is a synthetic analog of α-melanocyte stimulating hormone (α-MSH). It is 26-fold more potent than α-MSH at inducing adenylate cyclase activity in mouse melanoma cells in vitro. [Nle4,D-Phe7]-α-MSH also induces tyrosinase activity in a time-dependent manner in mouse melanoma cells. In vivo, [Nle4,D-Phe7]-α-MSH (1.8 μg/g) induces long-term skin darkening in R. pipiens (frogs). Formulations containing [Nle4,D-Phe7]-α-MSH have been used to induce melanogenesis in patients with erythropoietic protoporphyria.