Melanotan I (Afamelanotide)

Prescription

Melanotan I, now marketed as afamelanotide (Scenesse), is a synthetic tridecapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It is the only melanocortin agonist with regulatory approval in both the EU (2014) and the US (2019) — approved specifically for the prevention of phototoxicity in adults with erythropoietic protoporphyria (EPP), a rare genetic condition causing severe light sensitivity. Unlike its cousin Melanotan II, which is non-selective across melanocortin receptors (MC1R-MC5R) and carries sexual function and appetite effects, Melanotan I is relatively selective for MC1R — the primary receptor on melanocytes that drives eumelanin synthesis. By activating MC1R, afamelanotide stimulates melanogenesis independently of UV exposure, producing a photoprotective tan that absorbs harmful wavelengths and provides measurable UV protection. In Phase III trials for EPP, afamelanotide significantly increased the duration of pain-free sun exposure and improved quality-of-life scores in patients who otherwise could not tolerate any sunlight. The implant formulation (16 mg subcutaneous rod) provides sustained release over approximately 60 days. In the broader peptide community, Melanotan I is discussed as a potentially safer alternative to Melanotan II for cosmetic tanning, though it is not approved or marketed for this use. Its MC1R selectivity means it produces melanin stimulation with fewer of the off-target effects (nausea, sexual arousal, appetite suppression) associated with Melanotan II's broader receptor profile. However, the only commercially available formulation is the prescription implant for EPP — research-grade powder versions have not undergone the same quality controls.