Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn Melanotan What It Is and Its Relation to Skin Cancer Here's the part nobody explains when they're selling you the "Barbie drug.", , Melanotan 2 is a synthetic peptide that mimics alpha MSH a hormone your body already makes to tell your skin cells to Melanotan II: Tanning, Sexual Health Benefits, & Safety Concerns Melanotan is not a tan. It's an unregulated peptide with real risk. As a dermatologist, here's the reality: It has been linked to new and changing moles including cases of