Melanotan II
Also known as MT-2 · MT-II
Studied in small numbers of humans, usually for safety and pharmacokinetics rather than whether it works. A phase 1 result says almost nothing about effectiveness.
What it is
A synthetic cyclic analogue of alpha-MSH developed at the University of Arizona in the 1980s. Unlike its relative Melanotan I it is non-selective, activating melanocortin receptors across subtypes, which is the source of both its effects and its problems.
How it is thought to work
Non-selective melanocortin receptor agonist. MC1R activation stimulates eumelanin synthesis in melanocytes. MC3R and MC4R activation accounts for the effects on appetite and sexual arousal reported alongside pigmentation.
What the studies found
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Produces skin darkening
Small early human studies confirmed it increases melanogenesis. This effect is not disputed.
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Development was abandoned
It was never taken through the trial programme needed for approval. The selective MC1R analogue afamelanotide was developed instead, and the MC4R-selective bremelanotide was spun out separately.
What the evidence does not show
- No phase 2 or 3 trials exist. Almost everything known about its use in people comes from case reports of harm rather than controlled study.
- Because it hits several receptors, the effects people seek and the effects they do not are inseparable.
- Material sold online is frequently of unverified identity and purity.
Reported risks and adverse effects
- Multiple published case reports describe new or changing melanocytic naevi, and melanoma diagnosed after use. Causation is not established, but darkening existing moles also makes melanoma harder to detect visually.
- Rhabdomyolysis — severe muscle breakdown causing kidney injury — has been reported in case reports following use.
- Posterior reversible encephalopathy syndrome and renal infarction have each been reported.
- Common reported effects include nausea, facial flushing, spontaneous erections and appetite loss.
- The MHRA and other regulators have issued explicit public warnings against use.
This is a summary of what has been reported in the literature, not a complete safety profile. For anything concerning your own health, speak to a doctor.
Regulatory status
Not approved anywhere. Sale for human use is illegal in the UK and most jurisdictions. Regulators have repeatedly warned the public about it, and it is among the compounds most often seized in enforcement action.