melanotan i vs melanotan-ii

updated September 11, 2026

melanotan i (tier C) vs melanotan-ii (tier C): what each is, why each got its grade, half-life and source counts side by side.

melanotan i · tier C

approved as Scenesse for one rare skin condition. used off-label for tanning. long-term safety, unknown.

tier rationale

C-tier because the split between validated use and community use is unusually wide. The drug has real FDA approval for a narrow rare-disease indication with rigorous trial evidence. The grey-market cosmetic tanning use is a completely different use case with no long-term safety studies, concerning dermatological observations around nevus progression, and self-injection protocols far removed from the controlled implant administration the drug was actually approved for. Not B-tier because the specific use case the community buys it for is not the use case the evidence supports. Not D-tier because the pharmacology is real, the tanning effect is consistent and biologically plausible, and the drug itself has genuine regulatory standing. It no longer sits below melanotan ii. That ordering used to rest on melanotan ii carrying the deeper record, and on the published evidence it does not: melanotan i has two multicentre randomised double-blind placebo-controlled trials behind its approval (Langendonk 2015, N Engl J Med 373(1):48-59, PMID 26132941, 74 patients in the EU study and 94 in the US study) plus a randomised vitiligo trial (Lim 2015, JAMA Dermatol 151(1):42-50, PMID 25230094, 55 patients), while melanotan ii's entire human record is 23 subjects across three small studies from 1996 to 2000. The two now sit level at C, and on tanning specifically melanotan i is the better-evidenced of the pair.

melanotan-ii · tier C

skin tanning without sun. also triggers sexual arousal. both off-label. both widely used.

tier rationale

originally developed by University of Arizona researchers in the 1980s-90s as a potential skin cancer chemoprevention agent. The hypothesis was that stimulating endogenous melanin production could create protective pigmentation without UV exposure. no FDA-approved melanotan II product exists. commercial development was abandoned by Palatin in 2000 after the arousal-active metabolite (PT-141) appeared more promising. lives on entirely as a gray-market tanning compound. FDA, UK MHRA, Australian TGA, and multiple other regulatory bodies have issued warnings. C-tier because the published human record is three small placebo-controlled studies out of the University of Arizona between 1996 and 2000, 23 subjects in total, and only one of them is about tanning: Dorr 1996 (Life Sci 58(20):1777-84, PMID 8637402) was a phase I pilot in three male volunteers, of whom two showed increased pigmentation by reflectance. the other two are erectile-function crossover studies (Wessells 1998, J Urol 160(2):389-93, PMID 9679884, ten men; Wessells 2000, Urology 56(4):641-6, PMID 11018622, ten men). that is the board's C definition exactly: small studies, plausible mechanism, thin data. it was previously graded A on mechanism validity and consistent user reports, which is not what an A means here. not lower than C because the pigmentation effect is real, reproducible and dose-dependent; the melanoma case reports and gray-market product quality are the caveats that keep it from rising.

at a glance

reptides grades the research record and cites the literature behind every call. research reference only; not medical advice.