Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Informational only. Not medical advice.INFORMATIONAL PLATFORM ONLY — NOT MEDICAL ADVICE, DIAGNOSIS, OR TREATMENT
Head-to-head comparison of Melanotan I and Melanotan II — mechanism, side effects, legal status, and pricing.
Melanotan I (Afamelanotide) is a synthetic analog of alpha-MSH that selectively activates MC1R. FDA-approved as Scenesse for erythropoietic protoporphyria (EPP), it is distinct from Melanotan II and is studied for melanogenesis and photoprotection.
Melanotan II (MT-II) is a cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH) — Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2 — developed at the University of Arizona in the 1980s by Hruby, Hadley, and colleagues as a candidate photoprotection / sunless-tanning agent. It has never been approved by the FDA or any other regulator for any indication; clinical development was abandoned and it is sold only via grey-market research-chemical channels. Genuine safety signals have been reported, including darkening of existing moles, eruptive atypical nevi, and case reports of new primary melanoma in young tanning-seeking users.
Melanotan I
Melanotan II
Category
Legal Status
Mechanism
Half-life
Side Effects
COA-verified vendors · trust score ≥70 required · single-vial price — bulk/bundle deals may be lower
Melanotan I
Melanotan II
COA corpus from Disclosed Labs — independently tested batches only.
Melanotan I
50
COAs
99.7%
Avg purity
12
Labs
Melanotan II
60
COAs
99.7%
Avg purity
12
Labs
FDA-approved as Scenesse (Clinuvel, October 8, 2019) for increasing pain-free light exposure in adults with EPP, based on Phase III trials CUV039 and CUV040 showing more hours spent in sunlight without pain vs. placebo (Langendonk et al., NEJM, 2015; PMID 26132941). A randomized multicenter trial (Lim et al., JAMA Dermatology, 2015; PMID 25230094) also showed increased repigmentation when afamelanotide was combined with narrow-band UVB in vitiligo.
Melanotan II was developed by Hruby, Hadley, and colleagues at the University of Arizona in the 1980s. The seminal Phase I clinical study is Dorr et al. (Life Sciences, 1996; PMID 8637402), a pilot trial in three healthy male volunteers that documented dose-dependent pigmentation together with nausea, a 'stretching and yawning complex,' and spontaneous penile erections — the MC4R sexual-arousal signal that later motivated the development of bremelanotide (PT-141/Vyleesi). MT-II itself was never advanced to Phase III and has never received regulatory approval in any jurisdiction. As unregulated consumer use expanded through the 2000s, dermatology literature accumulated safety signals: Langan et al. (BMJ 2009, PMID 19174439) reported changes in moles among young users of unlicensed 'sun tan jab' preparations; Cardones & Grichnik (Arch Dermatol 2009, PMID 19380666) described alpha-MSH-induced eruptive atypical nevi in a patient with dysplastic nevi and prior melanoma who used MT-II; Evans-Brown et al. (BMJ 2009, PMID 19224885) documented widespread unregulated population use. Further case reports describe new primary cutaneous melanoma in young MT-II users and rare rhabdomyolysis. Regulators (FDA, UK MHRA, Australian TGA) have explicitly warned against use. Note: the Barnetson et al. 2006 photoprotection study (J Invest Dermatol, PMID 16763547) evaluated the related linear analog [Nle4-D-Phe7]-alpha-MSH (afamelanotide / Melanotan-I), not MT-II. Category 2 classification reflects documented safety concerns from non-selective melanocortin activation combined with oncologic signals.
Melanotan I and Melanotan II are both in the Cosmetic category and may have overlapping mechanisms. Researchers should review both profiles carefully, understand the mechanisms of action, and monitor the relevant biomarkers when combining compounds in the same class. As always, consult a licensed healthcare provider before making any decisions about combining research compounds.
This platform provides informational tools only, not medical advice. This comparison is for educational purposes only. Consult a licensed provider.
Contraindications
Lab Testing
Key references
Disclosed Labs