Case-report literature on mole changes and melanoma

Multiple published case reports describe melanomas emerging from existing moles during or shortly after Melanotan II use, and eruptive atypical nevi in users, including in a patient with a hereditary mole-melanoma syndrome; a causal link is not established, but the mechanism (direct stimulation of pigment-producing cells) makes this a genuine, seriously discussed concern rather than a generic caution.

Common adverse-effect data from user reports

Nausea and facial flushing are reported in roughly half or more of users, alongside injection-site reactions and unwanted spontaneous erections — a side-effect profile documented largely through case series and toxicology reports rather than controlled trials, since no legitimate trial program studies it for tanning use.

Severe toxicity case reports

Rare but serious outcomes have been documented in hospital case reports, including a case of rhabdomyolysis with acute kidney injury after a single injection — outcomes plausibly linked to both the drug's mechanism and the uncontrolled dosing and contamination risks of unregulated products.

Regulatory record

Health regulators in multiple countries, including Australia's TGA, have issued public warnings against Melanotan II specifically because it has never been evaluated or approved as a drug and is sold almost exclusively through unregulated online research-chemical channels.