What Is Melanotan II?

Also known as: MT2, MT-2

Melanotan II is a synthetic analog of alpha-MSH, the hormone that triggers melanin production. Developed at the University of Arizona in the 1990s with a sunless-tanning vision, it activates melanocortin receptors broadly — darkening skin with minimal UV, and famously also affecting libido and appetite.

It became one of the most-used gray-market peptides worldwide despite never approaching approval, largely through tanning and aesthetics communities. Its refined descendants did reach approval: PT-141 (libido) and afamelanotide (a niche photoprotection drug).

What is Melanotan II studied for?

Side effects & safety

Front-loaded and dose-dependent: nausea, flushing and spontaneous erections in the first doses. The dermatological caveat is serious — darkening of moles and freckles warrants skin monitoring, and dermatologists broadly advise against it for melanoma-risk reasons.

Legal & approval status

Research chemical; no approvals anywhere and explicit regulator warnings in several countries.

Typical dosing at a glance

Commonly reported protocols use 100 mcg–500 mcg, daily during loading, then 1–2x weekly, via subcutaneous injection. For the mixing math — how much bacteriostatic water, exact syringe units, doses per vial — see the Melanotan II reconstitution calculator →

Related peptides

What is PT-141?What is Kisspeptin-10?What is Gonadorelin?

Educational overview based on published research and commonly reported community protocols — not medical advice, and not an endorsement of any compound. Consult a licensed healthcare provider.