Melanotan II
Also referenced as: MT-2, MT-II
An unregulated tanning peptide with documented case-report harms and no approval.
- Evidence grade
- EExperimental / Limited Evidence
Experimental / Limited Evidence
- Regulatory status
- Not FDA Approved
Not approved anywhere as a medicine. Multiple regulators have issued warnings against unlicensed tanning injections. Afamelanotide, a different and more selective analogue, is separately approved for a rare photosensitivity disorder — the two should not be conflated.
- Human data
- Limited
No registered clinical trials identified
- Last reviewed
- September 1, 2026
Overview
Melanotan II is a non-selective melanocortin agonist that stimulates melanin production. It is sold online for cosmetic tanning despite regulatory warnings in multiple countries.
This entry exists for scientific literacy rather than as a research recommendation: the case-report literature is unusually clear about harm.
Why It's Being Studied
- Melanogenesis and photoprotection mechanisms.
- Melanocortin receptor pharmacology, which led to more selective approved analogues.
Mechanism of Action
It switches on the pigment-producing cells in skin, causing tanning without sun exposure, while also acting on other body systems.
Melanotan II is a cyclic lactam alpha-MSH analogue with non-selective agonism at MC1R (pigmentation), MC3R and MC4R (appetite, sexual function) and MC5R. Non-selectivity explains its broad off-target effects.
Research Areas & Routes Studied
- Pigmentation
- Melanocortin pharmacology
- Subcutaneous injection (unregulated use)
Evidence Summary
Human data are limited to small early studies and a substantial case-report literature documenting harm, including melanoma and systemic effects after unregulated use.
Human clinical evidence
- Small early pharmacology studies only; no efficacy or safety programme was completed.
Observational evidence
- A substantial case-report literature documents changing and new melanocytic lesions, melanoma diagnoses, rhabdomyolysis, renal injury and priapism following unregulated use.
Anecdotal / community information
- Cosmetic tanning forums; reports frequently omit adverse outcomes.
Reported Adverse Events in Research
- Nausea, flushing, spontaneous erections, appetite suppression.
- Darkening and change of existing naevi; melanoma has been reported after use.
- Case reports of rhabdomyolysis and renal injury.
- Unregulated products of unknown identity and sterility add infection risk.
Limitations of Current Evidence
- No controlled safety data at any dose.
- Regulatory warnings exist specifically because of documented harm.
Why It Is Used
- Sexual Health
Libido and Sexual Function
One of the few categories where the leading compound is FDA approved — and where its close relative is a clear example of what unselective signalling costs.
Read the case study
Research References
- Observational study
Melanoma and melanocytic lesions after melanotan use: case reports
- Regulatory document
Regulatory warnings on unlicensed tanning injections