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Melanotan II

Also known as: MT-II, MT-2, Melanotan-2

Research Only

Molecular Formula

C50 H69 N15 O9

Molecular Weight

1,024.18 Da

Half-Life

~33–40 minutes (plasma); 2–4 weeks biological persistence (pigmentation); 4–8 hours (erectile response)

Sequence

Ac-Nle-cyclo-NH₂

Clinical Applications & Evidence

Mechanism of Action

Non-selective agonist of central and peripheral melanocortin receptors. Activates peripheral MC1R to upregulate tyrosinase and induce eumelanin synthesis. Penetrates the blood-brain barrier to activate MC3R/MC4R in the hypothalamus and limbic system, suppressing appetite and stimulating sexual arousal. Modulates mast cell activation via MRGPRB2 and independent pathways.

Investigated Uses

  • Nonsegmental vitiligo
  • Erectile dysfunction (psychogenic and organic)
  • Erythropoietic protoporphyria
  • Obesity and metabolic syndrome
Moderate Clinical Data

Regulatory & Safety Status

FDA Status

Research Only

WADA / Athletic Status

Prohibited in Competition

Known Side Effects

NauseaFacial flushingSpontaneous erections (priapism)Yawning and stretching complexDecreased appetiteDarkening of existing neviMelanonychiaTransient hypertensionRhabdomyolysis (rare)Renal infarction (rare)

Contraindications

  • Personal or familial history of melanoma or atypical nevi
  • Uncontrolled hypertension
  • Cardiovascular disease
  • Pregnancy or lactation
  • Eating disorders

Drug Interactions

  • Phosphodiesterase type 5 (PDE5) inhibitors
  • Antihypertensives (α-/β-blockers)
  • Sympathomimetics
  • Diabetes medications

Citations & Clinical Trials

PubMed Melanocortin Receptor Agonists, Penile Erection, and Sexual Motivation ClinicalTrials.gov Melanotan II as an Adjunct to NB-UVB Phototherapy for Repigmentation in Stable Nonsegmental Vitiligo (MTII-VIT) FDA Notice of Category 2 Bulk Drug Substance Reclassification WADA 2026 Prohibited List