Melanotan II synthetic tanning drug mo Stock Image Science Source Images Melanotan II synthetic tanning drug molecule. 3D rendering. Not approved as drug. Atoms are represented as spheres with conventional color coding: h Stock Photo Alamy 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 Warning issued over increased use of 'Barbie drug' Melanotan II for Erectile Dysfunction: What the Evidence Shows and Practical Considerations Melanotan is trending again. As a dermatologist, I strongly need to tell you , Its an unapproved injectable peptide, and were seeing:, nausea and flushing, darkening of existing moles,