Research
What Is Melanotan I? Afamelanotide and Tanning Explained
Melanotan I is a synthetic version of a natural skin-darkening hormone. Unlike its better-known cousin Melanotan II, it became a real medicine: as afamelanotide (Scenesse), it is FDA-approved for a rare disorder that makes sunlight painful. This guide explains what Melanotan I is, how it works, how it differs from Melanotan II, what the research shows and why research powders are not the same as the approved drug.
Reviewed for accuracy · Last reviewed October 19, 2026
What Is Melanotan I?
Melanotan I (MT-1) is a 13-amino-acid synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH), the hormone that tells skin cells to make the pigment melanin. It was developed at the University of Arizona in the 1980s as a way to tan the skin without sun damage.
The drug name for Melanotan I is afamelanotide. Australian company Clinuvel developed it as Scenesse, a slow-release implant placed under the skin. It was approved in Europe in 2014 and by the FDA in October 2019.
How Does Melanotan I Work?
Melanotan I binds mainly to the melanocortin 1 receptor (MC1R) on melanocytes, the pigment cells of the skin.
- More melanin: it switches melanocytes toward making eumelanin, the dark brown pigment that absorbs UV light.
- Photoprotection: the extra pigment and antioxidant effects reduce skin damage and pain from light exposure.
- Selectivity: it is more selective for MC1R than Melanotan II, which also strongly activates MC3R and MC4R receptors linked to appetite and sexual arousal.
What Does the Research Show?
Erythropoietic protoporphyria (EPP). EPP is a rare genetic disorder in which light exposure causes severe burning pain. In phase 3 trials published in the NEJM in 2015, afamelanotide implants increased the time patients could spend in direct sunlight without pain and improved quality of life. This is the basis for its FDA approval.
Vitiligo. Clinuvel is testing Scenesse together with narrowband UVB light therapy for vitiligo, a condition where skin loses pigment. Earlier studies showed faster repigmentation with the combination than with light therapy alone, while afamelanotide alone did not repigment skin. The phase 3 trial CUV105 expects topline results in December 2026.
Other uses. It has also been studied in polymorphic light eruption and other light-sensitive skin conditions, with smaller trials.
| Area | What studies show | Evidence type |
|---|---|---|
| EPP (light-induced pain) | More pain-free sun exposure | Phase 3 RCTs; FDA-approved |
| Vitiligo (with UVB) | Faster repigmentation | Phase 2; phase 3 results due Dec 2026 |
| Cosmetic tanning | Darkens skin | Early studies; not approved |
Melanotan I Safety and Side Effects
In clinical trials of the Scenesse implant, the most common side effects were nausea, headache, implant-site reactions and darkening of moles and freckles. Because it darkens moles, the Scenesse label calls for regular skin checks. Unregulated research powder carries additional risks of contamination, wrong content and unsterile handling, and it has not been studied for cosmetic tanning.
Is Melanotan I FDA-Approved?
Yes, but only as Scenesse. Afamelanotide is FDA-approved as a 16 mg implant, given by trained doctors, to increase pain-free light exposure in adults with EPP. It is not approved for tanning or any cosmetic use. Research powder sold as “Melanotan I” or “MT-1” is not the approved product and is not equivalent to the licensed implant.
Melanotan I vs Melanotan II
| Feature | Melanotan I (afamelanotide) | Melanotan II |
|---|---|---|
| Structure | Linear, 13 amino acids | Cyclic, 7 amino acids |
| Receptors | Mainly MC1R | MC1R, MC3R, MC4R |
| Effects | Skin pigmentation | Pigmentation, appetite loss, arousal |
| Approval | FDA-approved (Scenesse) for EPP | Never approved |
| Spin-off drug | — | Bremelanotide (PT-141, Vyleesi) |
Melanotan I vs Melanotan II. Melanotan II is more potent and less selective, which is why it also causes nausea, appetite loss and spontaneous erections. Its sexual effects led to the development of PT-141 (bremelanotide). Melanotan I has a cleaner profile and a real approved use, but research powders of both carry the same quality risks.
Buying Research-Grade Melanotan I: What to Check
Products sold as Melanotan I by research suppliers are laboratory chemicals, not medicines. They are not made under drug manufacturing rules, so quality varies a lot between vendors. If you are evaluating a Melanotan I supplier for lab research, these are the checks that matter:
- Batch-specific COA: the certificate should match the lot number on your vial, not a generic sample.
- Independent lab: testing should come from a named third-party lab, ideally with a way to verify the report online.
- Identity, not just purity: HPLC purity alone does not confirm the right molecule; look for mass spectrometry (MS) identity confirmation.
- Endotoxin and sterility results: these matter for any injectable research material.
- Correct fill amount: the measured content should be close to the labeled milligrams.
Our Trusted Sources page lists vendors we track, with current community codes. Our guide to reading a certificate of analysis explains each line of a COA.
Key Takeaways
- Melanotan I is a synthetic α-MSH analog that darkens skin through MC1R.
- As afamelanotide (Scenesse), it is FDA-approved for the rare light-sensitivity disorder EPP.
- It is being tested with UVB light for vitiligo, with phase 3 results due December 2026.
- It is more selective and better studied than Melanotan II.
- It is not approved for tanning, and research powder is not the same as the approved implant.
Frequently Asked Questions
What is Melanotan I?
Melanotan I is a synthetic analog of the skin-darkening hormone α-MSH. Its drug name is afamelanotide, sold as the Scenesse implant.
Is Melanotan I FDA-approved?
Yes, as Scenesse, for adults with erythropoietic protoporphyria (EPP). It is not approved for tanning.
What is the difference between Melanotan I and Melanotan II?
Melanotan I is more selective for the pigment receptor MC1R and is an approved drug. Melanotan II also acts on appetite and sexual-arousal receptors and has never been approved.
Does Melanotan I help vitiligo?
Combined with UVB light therapy, it sped up repigmentation in earlier studies. Phase 3 results are expected in December 2026.
What are Melanotan I side effects?
In trials of the approved implant: nausea, headache, implant-site reactions and darkening of moles and freckles.
Sources
- Langendonk et al. (2015), NEJM – Afamelanotide for erythropoietic protoporphyria
- FDA (2019) – Scenesse (afamelanotide) implant approval and prescribing information
- Clinuvel – Vitiligo program update, CUV105 and CUV107 (July 2026)
- Lim et al. (2015), JAMA Dermatology – Afamelanotide and narrowband UV-B phototherapy for the treatment of vitiligo
MLCR SCTY provides educational information, not medical or legal advice. Research-use-only products are not intended for human consumption.