Melanotan I vs Melanotan II
Written and maintained by the AVERON Research Desk · Last reviewed September 2026
We do not sell either Melanotan to anyone who has a large number of moles, or any personal history of melanoma or skin cancer. Both darken existing moles, which makes changes in them harder to spot, and spotting those changes early is how skin cancer is caught.
Melanotan I and Melanotan II share a name, a parent hormone and a purpose — increasing skin pigment. But they differ in the one way that matters most: how many receptors they act on. That single difference explains nearly everything else about them, including why one became an approved medicine and the other did not.
The key difference: selectivity
Both mimic alpha-melanocyte-stimulating hormone, the natural hormone that tells skin cells to produce melanin.
Melanotan I, known as a drug as afamelanotide, acts mainly on the melanocortin 1 receptor, the one responsible for pigment.
Melanotan II is non-selective. It acts on several melanocortin receptors, including those involved in sexual arousal and appetite. That is why it causes spontaneous erections, changes in libido, reduced appetite and more nausea.
Side by side
| Melanotan I | Melanotan II | |
|---|---|---|
| Drug name | Afamelanotide | None |
| Receptors | Mainly MC1R (pigment) | Several melanocortin receptors |
| Effects on libido and appetite | Minimal | Common |
| Approved | Yes, as Scenesse, for EPP only | Never |
| Approved form | Implant placed by a clinician | None |
| Evidence level | Approved medicine | Early human data |
| Anti-doping | Not S0 | WADA S0 |
Melanotan I: a narrow approval
Afamelanotide is approved as Scenesse, in the European Union since 2014 and in the United States since 2019, for erythropoietic protoporphyria, a rare disorder in which light causes severe skin pain. A phase 3 trial published in the New England Journal of Medicine in 2015 showed it increased the time patients could spend in sunlight without pain.
The approved product is a 16 mg implant placed under the skin by a trained healthcare professional. It is not approved for cosmetic tanning, and there is no validated protocol for self-injection.
Melanotan II: never approved
Melanotan II was studied in small human trials in the 1990s, which showed it increased pigmentation and could induce erections. It never progressed to approval. Its research on sexual function contributed to the development of bremelanotide, now approved as PT-141.
Since then, the published literature on Melanotan II consists largely of case reports: melanoma, rapidly changing moles, prolonged erections, muscle breakdown and kidney problems. Regulators including the UK's MHRA and Australia's TGA have warned against it.
What both share
- Neither tans skin without ultraviolet light. Both amplify the skin's response to it.
- Neither protects against sun damage or skin cancer.
- Both darken existing moles and freckles.
- Neither has been studied for long-term cosmetic use.
Frequently asked questions
Doses mentioned on this page are the arms of published trials, given to describe their results. They are not guidance.
Sources
- Langendonk JG, Balwani M, Anderson KE, et al.. Afamelanotide for erythropoietic protoporphyria. New England Journal of Medicine, 2015;373:48–59. Link
- Hjuler KF, Lorentzen HF.. Melanoma associated with the use of melanotan-II. Dermatology, 2014;228(1):34–36. Link
- World Anti-Doping Agency. The Prohibited List. WADA. Link