Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn Melanotan II: Tanning injections, nasal sprays harmful to health You Should Avoid Using Nasal Tanning Sprays Melanotan II (MT2) Ottawa Peptides (PC) 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 Melanotan II PERMANENTLY Darkened My Skin!