What Is Melanotan I?
Melanotan I (Afamelanotide) is a synthetic linear analog of α-Melanocyte Stimulating Hormone (α-MSH), differing from the native 13-amino-acid hormone by a single substitution (Nle4, D-Phe7) that confers resistance to enzymatic degradation and significantly extends its activity duration. It binds MC1R on melanocytes, triggering melanin synthesis and natural skin darkening independent of UV exposure.
Mechanism and Clinical Approval
Melanotan I activates MC1R on melanocytes, initiating the cAMP signaling cascade that upregulates tyrosinase — the rate-limiting enzyme in melanin synthesis. Unlike UV-induced tanning (which causes DNA damage to trigger melanin production), Melanotan I stimulates melanin production directly without requiring mutagenic UV insult. Afamelanotide (Scenesse) received EMA approval in 2014 and FDA approval in 2019 for erythropoietic protoporphyria (EPP) — a rare genetic condition causing extreme photosensitivity — making it the first melanocortin agonist approved for human use.
Distinction from Melanotan II
Melanotan I is a linear peptide with primary MC1R selectivity. Melanotan II is a cyclic peptide with broader melanocortin receptor activity including MC3R and MC4R — producing additional effects on libido and appetite not shared by Melanotan I.
Quick Reference
Member reference tables summarize the compound's research parameters.
Research Indications
Research Protocols
As reported in cited literature and research-community logs (see Research Citations below), not a personal dosing recommendation.
This member section describes parameters reported in the research literature.
Peptide Interactions
This member section summarizes reported compound interactions and evidence limitations.
Reported Research Time Points
This member section summarizes reported research time points.
Safety Notes
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
This member section discusses research safety considerations and uncertainties.
Quality Indicators
Research Citations
- Evaluation of melanotan-I, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study
Dorr, R.T., Lines, R., Levine, N., et al., 2004, Life Sciences - Pharmacokinetics of [Nle4,D-Phe7]-alpha-MSH in rats and humans
Ugwu, S.O., Blanchard, J., Dorr, R.T., et al., 1997, Peptides - Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization
Hadley, M.E., Dorr, R.T., 2006, Peptides - Induction of skin tanning by subcutaneous administration of a potent synthetic melanotropin
Levine, N., Sheftel, S.N., Eytan, T., et al., 1991, JAMA - Melanotan I reduces the incidence of acute and chronic UV-induced skin damage
Barnetson, R.S., Ooi, T.K., Zhuang, L., et al., 2006, British Journal of Dermatology - The melanocortin-1 receptor is a key regulator of human cutaneous pigmentation
Abdel-Malek, Z., Scott, M.C., Suzuki, I., et al., 2000, Pigment Cell Research - Skin pigmentation and pharmacokinetics of melanotan-I in humans
Ugwu SO, Blanchard J, Dorr RT, 1997, Biopharm Drug Dispos - Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization
Hadley ME, Dorr RT, 2006, Peptides