Melanotan II (tanning peptide)

Tier 4 — risky / avoid · Illegal peptide · Melanoma risk · Priapism · Cardiovascular · Banned

A synthetic melanocortin receptor agonist developed for skin tanning and erectile dysfunction, abandoned by pharmaceutical development due to unacceptable adverse effects. Case reports document melanocytic lesion transformation to melanoma following Melanotan II use, with three separate cases published 2023–2024. Other effects include uncontrollable hyperpigmentation, spontaneous prolonged erections (priapism), nausea, facial flushing, and elevated blood pressure. Never received regulatory approval in any jurisdiction worldwide. Sold illegally online as "research chemicals." The desire for…

Dose: AVOID — never approved for human use; associated with melanoma transformation, priapism, and cardiovascular side effects. No safe dose established.