Melanocortin receptor agonist
Afamelanotide
EstablishedAlso known as Scenesse, Melanotan I, [Nle4, D-Phe7]-α-MSH
The tanning peptide that became an orphan drug for light intolerance.
- Cited sources
- 2
- Human-tested claims
- 1 of 1
- Best evidence
- Tier 1 · Established
- Status
- Approved
A stabilized α-MSH analog that darkens skin through MC1R. It is FDA-approved (Scenesse, 2019) as an implant for erythropoietic protoporphyria, a rare disorder where sunlight causes severe pain. It is the molecule grey-market 'melanotan I' claims to be.
How it works
Two substitutions make α-MSH resistant to breakdown and more potent at the melanocortin-1 receptor on melanocytes. The result is eumelanin production without UV exposure. In protoporphyria the extra pigment and the receptor's antioxidant effects raise the threshold for phototoxic reactions.
Sequence: Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH₂α-MSH with Met4→Nle and Phe7→D-Phe; linear, 13 residues.
What it's studied for
One claim per card, each with its own tier and source. Tiers 1 and 2 are human data. Tiers 3 and 4 are not yet.
- [1]Langendonk et al., 2015 (NEJM)(opens in a new tab)
Increased pain-free sunlight exposure and reduced phototoxic reactions versus placebo in two randomized trials in erythropoietic protoporphyria.
Established
Safety & limitations
The label lists implant-site reactions, nausea, headache and skin hyperpigmentation, and recommends full-body skin examination because the drug darkens existing moles and may make skin cancers harder to spot.
[2]FDA label – Scenesse (accessdata)(opens in a new tab)In the two pivotal trials adverse events were mostly mild and serious events were not judged drug-related. The approved product is a controlled-release implant; injectable 'melanotan I' sold online has none of that safety record.
[1]Langendonk et al., 2015 (NEJM)(opens in a new tab)Regulatory & legal status
FDA-approved (Scenesse, 2019) as a subcutaneous implant to increase pain-free light exposure in adults with erythropoietic protoporphyria; approved by the EMA in 2014.
[2]FDA label – Scenesse (accessdata)(opens in a new tab)Frequently asked
Is afamelanotide the same as melanotan II?
No. Afamelanotide is a linear α-MSH analog selective enough for MC1R to be approved as a drug. Melanotan II is a cyclic, broad-spectrum agonist that also hits MC4R, which is why it affects libido, and it was never approved.
Can it be used for cosmetic tanning?
It is approved only for erythropoietic protoporphyria and supplied as an implant through specialist centers. Cosmetic use is off-label and the online 'melanotan I' market is unregulated.
References
Written by Twenty Residues editorial. Medical review: pending; a named reviewer is being assigned.
Last updated October 1, 2026.
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Update history
- 2026-10-01 — Entry added.