In the 1990s, researchers at the University of Arizona were testing Melanotan II as a tanning agent. During clinical trials, they noticed something unexpected: the compound was causing spontaneous erections in male Figure 2 from Oral melanotic macule a case report. Semantic Scholar Change in moles linked to use of unlicensed sun tan jab The BMJ Figure 4 from Changes of melanocytic lesions inducedby Melanotan injections and sun bed use ina teenage patient with FAMMM syndrome Semantic Scholar