Melanotan II
Non-selective melanocortin receptor agonist (research peptide)
Status
Not approved
Not approved as a medicine anywhere, and illegal to advertise or supply in Australia; FDA has listed serious safety risks, and in April 2026 said its compounding advisory committee would review it before the end of February 2027.
Evidence
Preliminary
Human data come from tiny pilot studies in the 1990s plus case reports of harm from unregulated use.
In sport
WADAProhibited (WADA)
Melanotan II is a synthetic ring-shaped version of alpha-MSH, the hormone that darkens skin, developed at the University of Arizona and first tested in people in the 1990s. It was never approved, but is sold illegally online as a tanning injection or nasal spray.
Structure
7 residuesPoint at a bead, or focus the chain and use the arrow keys, to name it. Pick a chemistry to highlight it.
D-form (mirror image), shown in lower case
Sequence as text
Ac-Nle-D-H-D-Phe-R-W-K-NH2
What it is used for
- Sunless tanning (studied)
- Erectile dysfunction (studied)
- Tanning, libido, appetite suppression or weight loss outside trials (claimed, unproven)
How it works
Melanotan II activates several melanocortin receptors. On pigment cells (melanocytes) it stimulates production of melanin, darkening the skin without sun exposure. In the brain it acts on melanocortin pathways that influence sexual arousal and appetite, which explains the spontaneous erections, yawning and reduced appetite seen in early studies. Bremelanotide, an approved drug for low sexual desire, is a close structural relative.
How strong the evidence is
Preliminary
A 1996 pilot phase 1 study in three healthy men found increased skin pigmentation after only five injections, along with nausea, yawning, fatigue and spontaneous erections (Dorr 1996). A crossover trial in ten men with psychogenic erectile dysfunction found erections in eight of ten after melanotan II, with rigid erections lasting a mean 38 minutes versus 3 minutes on placebo (Wessells 1998). There are no large trials. A 2017 review of unregulated use described growing case reports of changing or new moles and four reports of melanoma, although causation is unproven (Habbema 2017).
Risks and side effects
- Nausea, flushing, yawning, fatigue and reduced appetite
- Spontaneous erections and priapism
- Darkening and changes in moles, with case reports of melanoma
- Case reports of posterior reversible encephalopathy syndrome (a brain swelling syndrome) and sympathomimetic toxicity
- Unlicensed products of unknown content and sterility
- Prohibited in sport at all times (WADA S0, non-approved substances)
Regulatory status
Status by country
| Jurisdiction | Status | Source |
|---|---|---|
| USUnited States | No authorised medicine | Source 5 |
| EUEuropean Union | No authorised medicine | Source 9 |
| UKUnited Kingdom | No authorised medicine | Source 10 |
| AUAustralia | No authorised medicine | Source 11 |
| CACanada | No authorised medicine | Source 12 |
Timeline
Sources
- 01Melanotan II (CID 92432)(opens the source in a new tab)
- 02Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study(opens the source in a new tab)
- 03Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study(opens the source in a new tab)
- 04Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review(opens the source in a new tab)
- 05Safety Risks Associated with Certain Bulk Drug Substances Nominated for Use in Compounding (Category 2)(opens the source in a new tab)
- 06FDA considers adding a dozen peptides to its bulk drug compounding list(opens the source in a new tab)
- 07What is Melanotan-II, the drug that the TGA urges consumers to avoid?(opens the source in a new tab)
- 08World Anti-Doping Code International Standard: Prohibited List 2026(opens the source in a new tab)
- 09Warning against the tanning product Melanotan(opens the source in a new tab)
- 10FOI 24/274: Side effects reports of melanotan II products(opens the source in a new tab)
- 11Melanotan II tanning peptide products found to be inconsistently dosed(opens the source in a new tab)
- 12Think twice before injecting peptides bought online: unauthorized products can seriously harm you(opens the source in a new tab)
Educational information, not medical advice. Talk to a licensed clinician before starting, stopping or changing any medicine.