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 Pathology Outlines Melanotic macule About Clinical Trials Melanoma Focus Figure 4 from Changes of melanocytic lesions inducedby Melanotan injections and sun bed use ina teenage patient with FAMMM syndrome Semantic Scholar COM Dec. 2011 Diagnosis UW School of Dentistry Change in moles linked to use of unlicensed sun tan jab The BMJ