What is Melanotan I?
Melanotan I, now known as afamelanotide and marketed as Scenesse, is a synthetic α-MSH analog that has achieved FDA approval. Unlike Melanotan II, it is highly selective for the MC1R receptor, producing melanin stimulation without significant sexual side effects.
Approved for erythropoietic protoporphyria (EPP), afamelanotide provides UV-free tanning and photoprotection for patients with severe sun sensitivity.
FDA Approval
Scenesse (Afamelanotide)
Approved for:
- Erythropoietic protoporphyria (EPP)
- Severe sun sensitivity
- Subcutaneous implant (16mg)
- Administered every 2 months
This represents one of the few melanocortin peptides to achieve full FDA approval.
Molecular Profile
Structure
Linear 13-amino acid peptide:
Ac-Ser-Tyr-Ser-Nle-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2
| Property | Value |
|---|---|
| Molecular Weight | ~1646 Da |
| Amino Acids | 13 |
| CAS Number | 75921-69-6 |
Mechanism
MC1R Selectivity
- Highly selective for MC1R
- Stimulates melanin production
- Provides photoprotection
- Minimal MC3R/MC4R activity
- No significant sexual effects
Comparison with MT-II
| Aspect | Melanotan I | Melanotan II |
|---|---|---|
| Structure | Linear, 13 aa | Cyclic, 7 aa |
| MC1R Selectivity | High | Moderate |
| Sexual Effects | Minimal | Significant |
| FDA Status | Approved (EPP) | Not approved |
| Tanning | Yes | Yes |
Summary
Melanotan I/afamelanotide represents successful pharmaceutical development of an α-MSH analog with FDA approval for photoprotection.
Key Points:
- Classification: Selective MC1R agonist
- Brand: Scenesse (afamelanotide)
- FDA Status: Approved for EPP
- Advantage: Selective, no sexual effects