Melanocortin

Melanotan 2 (MT-2)

Reviewed 22 October 2026 · How we research

Also known as: MT-2, MT2, Melanotan II, MT-II

What is Melanotan 2?

Melanotan 2 (MT-2, Melanotan II) is a synthetic version of alpha-melanocyte-stimulating hormone (α-MSH), the hormone that tells skin cells to make melanin. It was developed at the University of Arizona in the 1990s as a possible way to tan the skin without UV exposure and so reduce skin-cancer risk.

It never became a medicine. It is, however, widely sold online as “tanning injections” and nasal sprays, and the MHRA and NHS have repeatedly warned about it. Its close relative Melanotan 1 (afamelanotide) did become a licensed drug, and PT-141 was developed from it.

How Melanotan 2 works

MT-2 is a cyclic, shortened α-MSH analogue that is far more potent and longer-lasting than the natural hormone. It activates several melanocortin receptors: MC1R in skin pigment cells (tanning), MC4R and MC3R in the brain (appetite suppression and sexual arousal). Because it is non-selective, these effects come together — which is why nausea and spontaneous erections were common in the original studies.

What the research shows

• Phase 1 pilot studies in men in the 1990s showed tanning of the skin at low subcutaneous doses, with nausea, flushing, yawning and spontaneous erections as side effects (Dorr et al., 1996).
• Follow-up work on its erectogenic effect led to the development of bremelanotide (PT-141).
• Case reports have linked MT-2 use to rapidly changing moles, new atypical moles and melanoma; a causal link has not been proven.

Compare: Melanotan 2 vs PT-141

Melanotan 2 side effects

• Nausea and vomiting, facial flushing, yawning and stretching.
• Spontaneous erections and increased libido.
• Reduced appetite.
• Darkening of existing moles and freckles; new moles. Dermatologists report cases of melanoma in users.
• Rare reports of kidney problems and rhabdomyolysis.

Products bought online have no quality control, adding the risk of contamination and wrong dosing.

UK legal status

Melanotan 2 is not licensed in the UK, and selling or supplying it for human use is illegal. The MHRA has issued public warnings and seizes products. It remains legal only as a research chemical not intended for human use.

More detail, including current UK research-vial prices: Melanotan 2 UK guide. For the doses used in published studies and the reconstitution maths: Melanotan 2 dosing in the literature.

References

1. Dorr RT, et al. Evaluation of Melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study. Life Sci. 1996;58:1777–1784.
2. Hadley ME, Dorr RT. Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization. Peptides. 2006;27:921–930.
3. Habbema L, et al. Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review. Int J Dermatol. 2017;56:975–980.