Watch Me Tan with Melanotan 2 MT2 Year 2 Results, Side Effects, & My Full Protocol Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn Melanotan II for Erectile Dysfunction: What the Evidence Shows and Practical Considerations Your body already makes a hormone that tells your skin to tan. Melanotan 2 is a synthetic peptide engineered to mimic that hormone but in a version that's more potent and