Description
Melanotan-1 (afamelanotide) and Melanotan-2 are both synthetic analogs of the natural hormone α-MSH (alpha-melanocyte-stimulating hormone). They stimulate melanin production for skin tanning/photoprotection but differ significantly in structure and effects.
Brief descriptions
- Melanotan-1 (afamelanotide): A linear 13-amino-acid analog designed for greater stability and selectivity. It primarily activates the MC1R receptor on melanocytes, promoting eumelanin (dark pigment) synthesis. It is approved in some regions (as Scenesse implant) for treating erythropoietic protoporphyria (EPP) to reduce photosensitivity.
- Melanotan-2: A shorter, cyclic (lactam-bridged) heptapeptide. It is a potent, non-selective agonist at multiple melanocortin receptors (MC1R, MC3R, MC4R, MC5R).
Key comparison
| Aspect | Melanotan-1 | Melanotan-2 |
|---|---|---|
| Structure | Linear 13-aa analog | Cyclic 7-aa analog |
| Receptor selectivity | Preferential MC1R | Broad (MC1R + MC3R/MC4R/MC5R) |
| Primary effect | Skin tanning / photoprotection | Tanning + additional systemic effects |
| Other notable effects | Minimal | Appetite suppression, increased libido/sexual arousal, more nausea |
| Regulatory status | Approved (limited indication, e.g., EPP) | Not approved for any medical use |
| Typical side-effect profile | Milder, mostly local or mild systemic | More pronounced (nausea, flushing, spontaneous erections) |
Summary: Melanotan-1 is more selective and focused on pigmentation with a cleaner profile and some regulatory approval. Melanotan-2 produces stronger/faster tanning in many users but carries broader off-target effects (especially sexual and appetite-related) due to its non-selective receptor activity. Both are typically administered by subcutaneous injection in research or unregulated settings.
