What it is
Melanotan I is a peptide made of 13 amino acids. It is made in a lab. It copies alpha-MSH, a natural hormone that tells skin cells to make melanin. Melanin is the dark pigment in skin. Two amino acids were swapped so it breaks down slower and acts stronger than the natural hormone. It was built at the University of Arizona in the 1980s, the same program that made Melanotan II. It mainly acts on one receptor, called MC1R, found on pigment cells in the skin. Melanotan II acts on all five melanocortin receptors. See the Melanotan II entry for that compound. Other names: Afamelanotide, MT-I, NDP-MSH, Scenesse, CUV1647.
What researchers study it for
- Light sensitivity in erythropoietic protoporphyria, a rare genetic disease
- Skin darkening and melanin production
- Sunburn damage in skin cells
- Vitiligo and other light-related skin diseases
- How the body absorbs it by different routes
What the studies found
1. People with a rare light disease spent more time in the sun without pain.
Two 2015 phase 3 trials tested a slow-release implant every 60 days in people with erythropoietic protoporphyria. In this disease, sunlight causes severe burning pain. In the US trial, pain-free sun time over 6 months was 69.4 hours with the implant and 40.8 hours with placebo. In the European trial, painful light reactions dropped from 146 to 77. Most side effects were mild. Human data.
2. It darkened skin and cut sunburn cells when paired with UV light.
Three small 2004 studies gave volunteers Melanotan I with UV-B light or sunlight. Skin exposed to UV had 47 percent fewer sunburn cells. Sunburn cells are skin cells damaged by UV. People not given the peptide needed 50 percent more sun time to reach the same skin color. The tan lasted at least 3 weeks longer in the treated group. Nausea and face flushing were the main side effects. Human data.
3. Injection under the skin worked. Swallowing it did not.
A 1997 study gave 3 men Melanotan I by IV, by mouth, and by injection under the skin. Injection under the skin was fully absorbed. When swallowed, none showed up in the blood. It left the blood in about 1 to 2 hours. Skin on the face, arms, and neck darkened the most one week after dosing. This short blood time is why the approved form is a slow-release implant. Human data.
4. A review found trial data in other skin diseases.
This 2021 review looked at all published afamelanotide research. It found randomized trials in vitiligo and polymorphic light eruption, another light-sensitivity disease. Smaller studies looked at acne and solar urticaria. Darker skin all over was seen in almost all treated patients. This is a review, not new test data.
How much research exists
Phase 1 studies, two phase 3 trials, and smaller trials in other skin diseases. It is one of the most tested melanocortin peptides in humans. Long-term data in children does not exist.
Facts
- Formula: C78H111N21O19
- Weight: about 1647 g/mol
- CAS number: 75921-69-6
- Sequence: Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2
- Time in the blood: about 1 to 2 hours as a free peptide. The implant releases it over about 60 days.
- Storage: powder in the freezer, away from light.
Legal status
Approved by the FDA in 2019 as Scenesse, a 16 mg implant for adults with erythropoietic protoporphyria. Also approved in the European Union in 2014 for the same disease. It is not approved for tanning. Research-grade Melanotan I is not the approved product and is not approved for human use.
For research use only. Not for human use. Nothing here is medical advice.