Educational content only — this is not medical advice. Nothing here is a recommendation to buy, obtain, or use Melanotan II. Talk to a licensed clinician before making health decisions.
What it is
Melanotan II is a cyclic heptapeptide analog of alpha-MSH. It non-selectively activates melanocortin receptors, producing skin darkening (melanogenesis) and, in some studies, penile erection. It was investigated as a sunless tanning agent and for erectile dysfunction but never approved.
What the evidence shows
Early human studies confirmed skin tanning and erectile responses, but development stopped due to side effects. No robust RCT supports its use, and the evidence base is now dominated by case reports of adverse events from unregulated use.
Risks & unknowns
Reported adverse effects include nausea, flushing, yawning, stretching, decreased appetite, darkening of moles, new nevi, melanoma concerns, priapism, and cardiovascular effects. Unregulated injectable products are associated with infections and dosing errors. Melanoma risk is a theoretical but serious concern.
Legal / regulatory status
Melanotan II is not FDA-approved and is illegal to market for human use. Several countries have issued public health warnings. It is prohibited by WADA under S0.