Last updated: May 18, 2026
What Melanotan 2 is
Melanotan 2 is a synthetic cyclic heptapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH). Originally developed at the University of Arizona in the 1980s. Activates multiple melanocortin receptors (MC1R through MC5R) with non-selective binding.
Mechanism
- MC1R activation: stimulates eumelanin synthesis in melanocytes → skin pigmentation
- MC3R/MC4R activation: central effects on sexual function, appetite, energy expenditure
- MC5R activation: exocrine gland function
Reported effects
- Skin darkening (most prominent effect)
- Increased libido and spontaneous erection
- Mild appetite suppression
- Darkening of moles, freckles, and other pigmented lesions
Side effects
Common: Nausea, flushing immediately post-injection, increased libido, appetite suppression.
Less common: Darkened moles (concerning given melanoma risk), priapism (sustained erection), increased blood pressure.
Rare/serious: Reports of new melanomas in users (causal relationship unclear). Reports of rhabdomyolysis in case literature.
Regulatory status
Not FDA-approved for any indication. Sold as a research peptide. Banned in some EU countries. Most reputable medical authorities discourage human use due to safety concerns.
Melanotan 2 vs Melanotan 1 (afamelanotide)
Melanotan 1 (afamelanotide, brand name Scenesse) is FDA-approved 2019 for erythropoietic protoporphyria — a rare light-sensitivity disorder. MT-1 has more selective MC1R activity and a different safety profile. For any tanning purpose, MT-1 is the safer studied agent.
Is Melanotan 2 legal?<br />
Sold as a research peptide in some jurisdictions; not FDA-approved for human use. Banned in some EU countries.
How long do effects last?<br />
Skin pigmentation persists for weeks to months after a loading protocol. Other effects are dose-dependent.
What’s the difference between MT1 and MT2?<br />
MT1 (afamelanotide) is more selective for MC1R and is FDA-approved for a specific medical condition. MT2 activates multiple melanocortin receptors with less selectivity.
Does MT2 cause cancer?<br />
A definitive causal link to melanoma has not been established, but case reports of new melanomas in users have raised concerns. The peptide’s effect on existing moles is the most cited safety issue.