Melanotan II (MT-2)

The ten citations run from 1996 to 2025, and most describe use outside research settings. The only clinical trial is a 1996 pilot phase 1 study, which proposed a dose for later phase 1 studies. Six papers concern people using melanotan outside any trial: a 2017 review of reported risks, three case reports (two of melanoma and one of renal infarction, the last with a literature review), a qualitative analysis of online forum discussion and a survey posted to an online forum. The remaining three are laboratory studies: a peptide-stapling chemistry paper and two preclinical studies of feeding and thermogenesis.

The harm literature is descriptive. The 2017 review noted that several national health organisations had issued safety warnings about melanotan I and II, while acknowledging that conclusive evidence linking the reported events to the compounds was lacking. The authors of the renal report considered melanotan II the most likely cause of the infarction and raised thrombotic effects and direct kidney toxicity as possible mechanisms. The melanoma reports, from 2011 and 2025, each described a single case, the second in the oral mucosa with a review of the proposed association. The forum analysis found that people sought a tan, often before sun holidays or fitness and bodybuilding competitions. In the laboratory, microinjection into the nucleus accumbens lowered both the drive to eat and food intake without producing an aversive state or changing metabolic rate, and chronic treatment during cold acclimation partly rescued the impaired thermogenic capacity of PACAP-deficient mice. The stapled analogues bound with nanomolar affinity, one of them sub-nanomolar.

None of this shows how often harms occur or that the compound caused them. Case reports describe single events and cannot establish cause or rate, and the review does not quantify frequency. The forum studies rest on self-reported accounts from people who chose to take part. The one trial is thirty years old and was a pilot, and the feeding, thermogenesis and binding findings each come from a single study. The cited evidence therefore says more about the circumstances of unregulated use than about the compound's pharmacology in people.