Cosmetic
Melanotan II
Non-selective melanocortin agonist producing tanning and libido effects — not FDA-approved.
- Half-life
- ~30 minutes (plasma); pigmentation effects last weeks.
- Route
- Subcutaneous
Overview
Melanotan II is a synthetic cyclic peptide analogue of alpha-MSH developed at the University of Arizona in the 1980s, originally as a photoprotection strategy for pale-skinned patients.
Mechanism of action
Broad agonism of MC1R (melanogenesis), MC3R and MC4R (appetite, sexual arousal). PT-141 was later derived from it to focus on MC4R activity.
Evidence base
Small early-phase trials confirmed tanning effect and libido enhancement. Development halted; product never approved. Widely used in the grey market.
Typical dosing
Loading protocols vary; commonly 0.25–1 mg subcutaneously daily until pigmentation, then twice weekly maintenance. Open the dose calculator →
Safety & contraindications
Nausea, flushing, focal hyperpigmentation and new atypical naevi are frequent. Case reports of melanoma diagnosed after use — not causal but concerning. Full-body skin surveillance recommended if used at all.
Related peptides
Educational reference only. Nothing on this page is medical advice, a prescription, or an offer to sell. Discuss any peptide therapy with a qualified clinician who can evaluate your history and monitoring needs.