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Melanotan II

Also sold as MT-2, MT2.

Half-life
14 h
Steady state
~3 d
Class
Skin
Category
Peptide

Published population averages. Steady state is the usual five half-life rule of thumb, not a measurement. See peptide half-life, explained.

Overview

Melanotan II (MT-II) is a synthetic analogue of alpha-melanocyte stimulating hormone (α-MSH) that activates melanocortin receptors (MC1R–MC5R). Originally developed at the University of Arizona for UV-free tanning, it also produces appetite suppression and sexual arousal effects due to its non-selective melanocortin activity.

How it works

Non-selectively activates melanocortin receptors: MC1R (melanogenesis — tanning without UV), MC3R/MC4R (sexual function and appetite), MC5R (sebaceous glands). Stimulates melanocytes to produce eumelanin, darkening skin pigmentation. MC4R activation in the hypothalamus produces sexual arousal and satiety. Cyclic structure provides resistance to enzymatic degradation.

Half-life and peak

Half-life approximately 14 hours (longer than native α-MSH due to cyclization). Skin darkening onset 5–7 days with loading protocol. Sexual effects onset within 1–4 hours post-injection. Typical dose: 250–500 mcg subcutaneous.

What it is studied for

UV-independent tanning (MC1R), erectile dysfunction (MC4R), female sexual dysfunction, appetite suppression, photoprotection for erythropoietic protoporphyria.

Research status

Not FDA-approved. University of Arizona licensed derivatives (PT-141/Bremelanotide, now FDA-approved for HSDD). MT-II itself was never developed as a pharmaceutical. Widely used off-label. Safety concerns include nevi darkening and theoretical melanoma risk.

Sources

Educational reference only. This page describes what is published about a compound; it is not medical advice, not a recommendation to take anything, and not a dosing guide. Several compounds in this catalog are investigational and are not approved medicines. Talk to a doctor.