Melanotan II

Overview

Melanotan II is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH) that stimulates melanin production, causing skin darkening. It was originally developed at the University of Arizona for preventing skin cancer via increased tanning, but was never FDA-approved.

Mechanism of Action

Melanotan II is a non-selective melanocortin receptor agonist, binding to MC1R (pigmentation), MC3R (energy homeostasis), MC4R (sexual function and appetite), and MC5R (exocrine glands). MC1R activation stimulates melanogenesis in melanocytes, while MC4R activation produces sexual arousal effects.

Research Summary

Phase 1 and 2 clinical trials demonstrated dose-dependent skin darkening and sexual arousal side effects. It has never progressed to FDA approval due to safety concerns. The related compound PT-141 (bremelanotide) was developed from Melanotan II specifically for sexual dysfunction.

Dosing Information

Reported Side Effects

• Nausea (especially at higher doses)
• Facial flushing
• Appetite suppression
• Spontaneous erections
• Mole darkening (requires monitoring)
• Fatigue

Research References

• Subcutaneous administration of Melanotan II to human volunteers: a phase I study (2000)
• Melanotan II — a potential future treatment for erectile dysfunction (1996)
• Melanocortin peptides: potential targets in the treatment of obesity and sexual dysfunction (2004)