Melanotan-I (afamelanotide)
Few melanocortin agonists have regulatory approval. Melanotan-I (afamelanotide) is one of them: approved for a rare disease, it is also a reference for understanding melanogenesis.
- Research Use Only
- Molecule under study
- Living document
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- Current research state
- An approved molecule (Scenesse®) for erythropoietic protoporphyria. PHL presents it as Research Use Only.
- Current clinical phase
- FDA (2019) and EMA (2014) approval — rare indication
- Last update
- 21 July 2026 · Reference fact sheet v1.0
- Living document
- Updated regularly as research progresses.
What is Melanotan-I (afamelanotide)?
Melanotan-I, also called afamelanotide, is a linear peptide of 13 amino acids and a synthetic analogue of α-MSH (α-Melanocyte Stimulating Hormone).
It was developed at the University of Arizona in the 1980s to induce protective skin pigmentation without prolonged sun exposure.
Unlike Melanotan-II, it is linear (non-cyclic); its documented effects are mainly pigmentary, with fewer extra-pigmentary effects reported, although its selectivity for MC1R remains relative.
Names you may come across
This molecule may appear under several names in the scientific, clinical or technical literature. Here are the main designations you may come across.
International nonproprietary name (INN).
Original research name.
Brand name (Clinuvel Pharmaceuticals), approved by the FDA/EMA for EPP.
Understanding it simply
Three simple reference points for understanding Melanotan-I.
A tan without UV
It stimulates the cells that produce the skin's brown pigment (eumelanin), without necessarily requiring sun exposure.
Mainly pigmentary
Compared with Melanotan-II, its reported effects mainly concern pigmentation (MC1R receptor), with fewer described effects on libido or appetite.
An approved medicine
Under the name Scenesse®, it is approved in the United States and Europe for a rare disease (erythropoietic protoporphyria).
What research shows today
Science advances step by step. We clearly distinguish what is firmly established from what remains under study.
- A linear tridecapeptide with the structure Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2, an analogue of α-MSH. — established
- Melanocortin receptor agonist (MC1R, but also MC3R to MC5R); its pigmentary effects are mediated mainly through MC1R, expressed on melanocytes. — established
- Stimulates the production of eumelanin (brown/black pigment), which provides photoprotection against UV and visible light. — established
- Demonstrated efficacy and tolerability in erythropoietic protoporphyria (EPP). — established
- Use in vitiligo, polymorphic light eruption and other photodermatoses is being explored. — ongoing
A molecule approved by the FDA and EMA for a rare indication (EPP) on the basis of randomized clinical trials. Other uses remain experimental.
What the research shows
- Well-characterized melanocortin pharmacology: MC1R > MC3R/MC4R/MC5R agonism.
- Stimulation of eumelanin melanogenesis demonstrated in vitro and in vivo.
- Randomized clinical trials in erythropoietic protoporphyria — a modest but significant increase in the duration of pain-free light exposure (Langendonk et al., 2015).
- FDA (2019) and EMA (2014) approvals under the name Scenesse®.
What still remains to be studied
- Efficacy and safety in vitiligo, polymorphic light eruption and other photodermatoses.
- Effects of induced pigmentation on long-term melanoma risk — reassuring data, but monitoring is recommended.
- Optimization of administration regimens (subcutaneous implants versus injections).
What we know today
Not all information carries the same weight of evidence. We therefore present it across three clearly distinct levels, from the most solid to the most indicative.
What scientific publications show
Scientific evidence- Activation of MC1R on melanocytes increases cAMP production and triggers the expression of tyrosinase, a key enzyme in eumelanin synthesis.
- Trials in EPP show a longer duration of pain-free light exposure and an improvement in quality of life, both of modest magnitude.
- The short-term tolerability profile is well documented; long-term follow-up continues through post-approval registries.
What some professionals report
Documented- In EPP, afamelanotide is the first approved option aimed at increasing light tolerance; its benefit remains modest in magnitude.
- Recommendations emphasize regular skin monitoring (screening for pigmented lesions).
What the community reports
Field observations- Community reports describe progressive skin darkening and the appearance of pigmented spots (ephelides).
- These individual observations do not replace clinical data or medical advice.
The evidence is strong for the approved indication (EPP); it remains exploratory for most other uses.
How does Melanotan-I (afamelanotide) work?
Melanotan-I acts on melanocortin receptors, primarily MC1R, expressed on melanocytes in the skin.
- MC1R receptor (melanocytes)
- A G protein-coupled receptor and the primary target; its activation increases intracellular cAMP.
- Tyrosinase
- A key enzyme in melanin biosynthesis, whose expression is induced by the MC1R/cAMP pathway.
- Melanocytes
- Melanin-producing cells — increased eumelanin (photoprotective).
- Keratinocytes
- Recipients of melanosomes transferred from melanocytes — visible skin darkening.
The effect is mainly dermatological; extra-pigmentary effects (appetite, libido) are reported less often than with Melanotan-II, as afamelanotide's selectivity for MC1R is relative rather than absolute.
Clinical trials timeline
A molecule under study progresses step by step. Here, simply, is where the research currently stands.
- Discovery· 1980sCompleted
Development at the University of Arizona
Victor Hruby and Mac Hadley synthesize a stable α-MSH analogue to explore photoprotection.
- Preclinical· 1990sCompleted
Characterization of melanogenesis
Demonstration of eumelanin induction in vitro and in animal models.
- Phase 2· 2000sCompleted
Trials in EPP
Early clinical studies in erythropoietic protoporphyria showing improved light tolerance.
- Approval· 2014Completed
EMA authorization (Scenesse®)
The European Medicines Agency approves afamelanotide for EPP.
- Approval· 2019Completed
FDA approval (Scenesse®)
The FDA subsequently approves afamelanotide for EPP on the basis of randomized trials.
Available analyses
No analytical document has been published for this molecule to date.
Open the analysis libraryFrequently asked questions
Is Melanotan-I an approved medicine?
Established: yes, under the name Scenesse® (afamelanotide), approved by the FDA and EMA for erythropoietic protoporphyria, a rare photosensitivity disorder.
How does it differ from Melanotan-II?
Established: Melanotan-I is a linear peptide with 13 amino acids, more selective for the MC1R receptor (pigmentation); Melanotan-II is a shorter, less selective cyclic peptide with effects on libido and appetite.
Can it replace sun protection?
Established: no. The induced pigmentation contributes to photoprotection but does not replace conventional measures (clothing, sunscreen, sun avoidance).
What adverse effects have been reported?
Established: nausea, headache, injection-site reactions, generalized skin darkening, and the appearance of ephelides (freckles). Dermatological monitoring is recommended.
Is it free of long-term risks?
Further study needed: post-approval data in EPP are reassuring, but prolonged off-label exposure remains poorly documented.
Can it treat vitiligo?
Further study needed: preliminary trials suggest potential benefit in combination with phototherapy, but no approval has been granted for this indication.
Scientific publications
Selected reference publications on afamelanotide / Melanotan-I — melanocortin pharmacology, clinical trials in EPP, and regulatory approvals. An evolving bibliography.
Discovery and development of novel melanogenic drugs. Melanotan-I and -II
Hadley M. E., Hruby V. J. et al. · Pharmaceutical Biotechnology · 1987
Glossary
- α-MSH
- α-Melanocyte Stimulating Hormone — a naturally occurring hormone derived from POMC and an agonist of melanocortin receptors.
- MC1R
- Melanocortin receptor type 1, expressed on melanocytes; the main regulator of eumelanin synthesis.
- Eumelanin
- A brown/black skin pigment that provides photoprotection against UV and visible light.
- Melanogenesis
- The biochemical processes involved in melanin production within melanocytes.
- Erythropoietic protoporphyria (EPP)
- A rare genetic disease causing painful photosensitivity to visible light.
- Tyrosinase
- A key enzyme in the biosynthesis of melanin from tyrosine.
Continue your discovery
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Reference fact sheet — version 1.0, updated on 21 July 2026. The full regulatory and scientific framework is gathered in the “Important information” box at the top of the fact sheet.