Melanotan 2 (MT-2)
Melanotan 2 is a synthetic analogue of alpha-melanocyte-stimulating hormone (alpha-MSH) developed in the early 1990s. It stimulates melanogenesis and has been studied for tanning, sexual function, and appetite suppression — but carries a notable safety and legal profile that warrants careful consideration.
What is Melanotan 2?
Melanotan 2 (MT-2) is a cyclic heptapeptide analogue of alpha-MSH, developed at the University of Arizona as part of research into melanocortin receptor agonists. It acts primarily on the MC1R (melanocortin 1 receptor) to stimulate melanin production in skin cells, producing a darkening effect without UV exposure.
MT-2 also has significant affinity for MC3R, MC4R, and MC5R, which accounts for its broader systemic effects including sexual arousal, appetite suppression, and cardiovascular activity. It is distinct from Melanotan 1 (afamelanotide), which has a more selective melanotropic profile.
How It Works
MC1R Agonism — Tanning
By binding to MC1R on melanocytes, MT-2 triggers the production of eumelanin (brown/black pigment), leading to skin darkening. This effect is UV-independent, though UV exposure may amplify it. The resulting tan is considered cosmetically similar to a sun-induced tan but may not confer the same photoprotective benefits.
MC4R Agonism — Sexual & Appetite Effects
Activation of MC4R in the hypothalamus contributes to spontaneous erections in male subjects (a well-documented effect in early clinical trials), as well as libido effects in both sexes and appetite suppression. These off-target effects are prominent and contribute significantly to the adverse effect profile.
Research Overview
Early Phase I and Phase II trials were conducted in the 1990s and early 2000s at the University of Arizona. Development of MT-2 for pharmaceutical use was eventually discontinued in favor of the more selective MT-1 analogue (afamelanotide, now approved in some markets for erythropoietic protoporphyria). The research record for MT-2 is therefore predominantly from this early-phase period.
- Tanning efficacy: Phase II trials demonstrated significant skin darkening at doses of 0.025 mg/kg administered subcutaneously, with effects appearing within days of starting a course.
- Sexual function: Early trials noted spontaneous erections as a prominent side effect in male subjects. Subsequent research explored MC4R agonists for erectile dysfunction, leading to the separate development of bremelanotide (PT-141), which is now FDA-approved for hypoactive sexual desire disorder in premenopausal women.
- Nevi (mole) changes: Case reports and observational data have linked MT-2 use to changes in pre-existing moles and new nevi formation, raising melanoma concern flags in regulatory assessments.
Safety Concerns
- Nausea, facial flushing, and spontaneous erections are common acute side effects even at low doses.
- Changes to moles (nevi) have been reported, with unresolved questions about melanoma risk after prolonged use.
- No long-term human safety data exists — pharmaceutical development was halted before such studies were completed.
- Unregulated gray-market products may be mislabeled, underdosed, overdosed, or contaminated.
- Cardiovascular effects (blood pressure changes) have been noted in early clinical data.
- Interactions with other medications or peptides are not characterized.
Legal Status
The legal status of Melanotan 2 varies significantly by jurisdiction and is subject to change. It is not approved for therapeutic use in the United States, European Union, United Kingdom, Australia, or Canada. In many markets it exists in a gray-market area — not explicitly scheduled as a controlled substance in all jurisdictions, but also not legally sold for human use.
United States
Not FDA-approved. The FDA has issued import alerts and warning letters related to MT-2 products. It may be sold as a “research chemical” but human use is not legally sanctioned.
United Kingdom
The MHRA has issued warnings against MT-2 use and classified it as an unlicensed medicine. Sale for human use is illegal.
Australia
Listed as a Schedule 4 prescription-only substance by the TGA, making unsupervised use and gray-market purchase illegal.
Always verify the current legal status in your jurisdiction before researching or purchasing any peptide. This information may not be current.
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Disclaimer
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