What it is
Melanotan I is the original research name for afamelanotide, a synthetic version of alpha-melanocyte-stimulating hormone (alpha-MSH). Alpha-MSH is the body's own signal that tells pigment cells to make melanin. The natural hormone breaks down quickly; afamelanotide swaps two amino acids (norleucine at position 4, D-phenylalanine at position 7) so it lasts longer and binds more strongly.
It started life as a tanning compound. It ended up as the only melanocortin tanning peptide to become an approved medicine, and not for cosmetic use. The European Medicines Agency authorised it on 22 December 2014 under exceptional circumstances, and the US FDA approved it in October 2019, both as Scenesse, a 16 mg implant for erythropoietic protoporphyria (EPP).
How it works
Afamelanotide activates the melanocortin 1 receptor (MC1R) on melanocytes. The FDA label describes the result as increased eumelanin, the brown-black pigment, produced without needing UV exposure. Eumelanin absorbs light before it reaches deeper cells.
In EPP, a genetic defect lets a light-sensitive compound (protoporphyrin IX) build up in the skin. Visible light then triggers intense burning pain within minutes of sun exposure. More eumelanin in the skin means less light reaches that protoporphyrin, which is the logic behind using a tanning peptide as a medical treatment.
What the research found
Human trials. The pivotal evidence is two randomised, placebo-controlled trials published together in the New England Journal of Medicine (Langendonk and colleagues, 2015):
- In the US trial (94 patients, 6 months), median pain-free time in direct sunlight was 69.4 hours with afamelanotide versus 40.8 hours with placebo.
- In the EU trial (74 patients, 9 months), median pain-free time was 6.0 hours versus 0.8 hours, and there were fewer phototoxic reactions (77 versus 146).
- Quality of life improved in both trials. Most adverse events were mild, and serious adverse events were not considered drug-related.
The EMA noted that complete information on benefits could not be gathered, partly because EPP is so rare. That is why the EU approval came under exceptional circumstances.
Tanning in healthy people. Melanotan I was first developed as a sunless tanning agent. That use was never approved anywhere.
Side effects reported in studies
From the FDA label (Scenesse vs vehicle implant):
| Event | Afamelanotide | Vehicle |
|---|---|---|
| Implant site reaction | 21% | 10% |
| Nausea | 19% | 14% |
| Oropharyngeal pain | 7% | 5% |
| Fatigue | 6% | 3% |
| Skin hyperpigmentation | 4% | 0% |
The label warns that afamelanotide can darken existing moles and freckles and increase overall pigmentation, and it recommends a full-body skin examination twice a year. That recommendation exists because any drug that stimulates melanocytes makes changing moles harder to judge.
Melanotan I vs melanotan II
| Melanotan I (afamelanotide) | Melanotan II | |
|---|---|---|
| Structure | Linear, 13 amino acids | Cyclic, 7 amino acids |
| Main receptors | MC1R | MC1R plus MC3R, MC4R |
| Arousal and appetite effects | Not a feature | Prominent |
| Regulatory status | Approved (Scenesse, EPP) | Never approved; regulator warnings |
The practical difference is selectivity. Melanotan II reaches the brain receptors that PT-141 was later built around, which explains its spontaneous erections and nausea. Melanotan I stays mostly on the pigment receptor.
Status in the Philippines
Scenesse is not registered with FDA Philippines. As an approved medicine abroad, prescribing belongs with a licensed Philippine physician. Powder sold locally as "melanotan 1" is an unregistered research product. It is not the dissolving implant that was tested, so the trial data above does not describe it.
Local demand is small. Most Filipino skin is Fitzpatrick type III to V, and the domestic market leans towards lightening rather than tanning.
Storage
The research powder is best kept refrigerated and away from light. After reconstitution with bacteriostatic water, store at 2 to 8°C. In a Manila brownout, move vials to a cooler with ice packs rather than leaving them in a warming fridge. See the beginner guide for handling basics.
