A long-acting copy of the skin-darkening hormone alpha-MSH, FDA-approved as the Scenesse implant for a rare light-pain disorder.
Also called Afamelanotide, Scenesse, MT-1, Melanotan I, [Nle4, D-Phe7]-alpha-MSH, NDP-alpha-MSH, CUV1647, EP1647
Melanotan-1 is the research name for afamelanotide, a 13-amino-acid copy of alpha-MSH, the hormone that tells pigment cells to make dark melanin. Two amino acids were swapped at the University of Arizona in 1980 so it lasts far longer in the body than the natural hormone. It binds the MC1 receptor on melanocytes, and the skin darkens without sun exposure.
It is the only melanotan with a real approval. As Scenesse, a 16 mg implant the size of a grain of rice placed under the skin above the hip every 2 months, it is approved in the EU (2014) and the US (2019) for adults with erythropoietic protoporphyria, a rare genetic disease where a few minutes of sunlight cause burning pain. In two placebo-controlled trials, patients on the implant could stay in direct sun longer without pain, for example a median 69.4 hours over 6 months versus 40.8 hours on placebo in the US study.
What people buy online as 'Melanotan 1' for cosmetic tanning is a different thing: an unregulated powder of unknown purity, injected daily, with no approval for tanning anywhere. Early Arizona volunteer studies did show daily injections darkened the face, neck and forearms and roughly doubled eumelanin in forearm skin, but the approved product's label still asks for a full skin check twice a year because it darkens existing moles and freckles.
What it binds to, and what happens inside the body after that, step by step.
Afamelanotide binds and activates the melanocortin 1 receptor (MC1R) on melanocytes, the pigment cells in skin. That raises cAMP inside the cell and switches melanin production toward eumelanin, the brown-black pigment that absorbs light. The darker skin filters the visible light that triggers pain in protoporphyria. It works without UV exposure, unlike a normal tan.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
For EPP the evidence is solid: two multicenter placebo-controlled RCTs (168 patients combined) plus a third trial on the FDA label show more pain-free time in sunlight and fewer phototoxic reactions, and 8 years of observational data in 115 patients show sustained quality-of-life gains. For vitiligo there is one small RCT (55 patients) showing faster repigmentation when added to UV-B light; Phase III results are pending. For cosmetic tanning there are only small 1990s and 2000s volunteer studies showing it darkens skin; no trial has tested whether cosmetic users are better off, and nobody has studied the unregulated powders.
168 adults with EPP in two trials (74 in the EU, 94 in the US)
Pain-free direct sun exposure over 6 months was a median 69.4 hours on afamelanotide vs 40.8 hours on placebo in the US trial (P=0.04); phototoxic reactions were 77 vs 146 in the EU trial.
Read the study115 EPP patients in Rome and Zurich, 1,023 implants over up to 8 years
EPP quality-of-life scores rose from 31% of maximum before treatment to 74% and stayed there; only 3 patients stopped because it did not help enough.
Read the study55 adults with nonsegmental vitiligo, skin types III to VI
Repigmentation at day 168 was 48.6% with implant plus UV-B vs 33.3% with UV-B alone, and the face started repigmenting at 41 vs 61 days; the benefit was seen in darker skin types IV to VI, not type III.
Read the study7 healthy volunteers, skin types III to IV
Ten daily injections of 0.16 mg/kg raised forearm eumelanin by a mean 98% one week after dosing, with tanning of the face, neck and forearm.
Read the study28 healthy volunteers across three phase 1 studies
In the first study, the 3 of 4 MT-1 subjects who tanned had 47% fewer sunburn cells after UV-B; in the third, sunlight-only controls needed 50% more sun time to reach the same tan.
Read the study3 healthy men, IV, oral and subcutaneous dosing
Subcutaneous dosing was fully bioavailable, oral dosing produced no detectable blood levels, and the tan peaked 1 week after dosing and was still present at 3 weeks.
Read the studyNo preclinical studies are listed as key studies here. The human data above carries the evidence.
These are questions the published research has not answered.
Scenesse is approved only for adults with EPP. It is not approved for cosmetic tanning, vitiligo or any other use. A Phase III vitiligo trial (CUV105, 210 patients, implant every 3 weeks plus narrowband UV-B vs UV-B alone) has finished enrolling; in July 2026 the company said topline results are due in December 2026, and none had been published as of this review. An EU application to extend the label to adolescents (narrowed during review to ages 15 to 17 and over 60 kg) was withdrawn on April 24, 2024, because the company could not supply the safety and efficacy data EMA asked for. Afamelanotide is not named on the WADA Prohibited List, and because it is an approved drug it falls outside the S0 catch-all for unapproved substances. Powders sold online as 'Melanotan 1' are unregulated research chemicals, not Scenesse.
How much of Melanotan-1 (afamelanotide) is left after a single dose
Simple first-order model from the published half-life. Real clearance varies with dose, route, kidney and liver function and formulation. This is not a dosing schedule.
This table records the doses that trials and approved labels used, with the source for each row. It is a record of research, not a recommendation, and it is open to free members.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
The approval covers one product: the Scenesse implant made under drug manufacturing standards, for EPP. Vials sold online are unregulated powders with no verified identity, purity or dose, and are not approved for tanning anywhere.
Volunteer studies in the 1990s and 2000s showed daily injections darkened the face, neck and forearms and raised eumelanin without UV. The effect is stronger when combined with sunlight.
The FDA label tells EPP patients to keep using sun and light protection. Early data showed fewer sunburn cells, but no study has shown that it prevents skin cancer.
No study has tested this. Case reports of new or changing moles and melanomas exist mostly for unregulated melanotan products, and they cannot prove cause. Long-term EPP data up to 8 years did not show a cancer signal, but those studies were not designed to find one.
Afamelanotide mainly acts on MC1R in the skin. The sexual effects seen with melanotan-2 and bremelanotide come from MC4R in the brain, and spontaneous erections are not a reported side effect of afamelanotide.
Not applicable to Scenesse, which is a solid implant. The label says to keep it in the refrigerator at 2 to 8 C (36 to 46 F), protected from light.
Scenesse is never reconstituted. No published stability data exist for research-grade afamelanotide powders after mixing.
One email when a trial reads out, a label changes or the FDA acts on a peptide. Free, no selling of peptides, unsubscribe any time.