Health expert says Melanotan II darkens skin moles and can make melanoma hard to detect Herald Sun 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 Reminder of serious health risks with 'Melanotan 2' self tan products Irish Pharmacist Tanning peptides like melanotan are trending online, but theyre not approved, not regulated, and illegal to advertise in Australia. When products havent been properly tested, theres no way to know Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn