Health expert says Melanotan II darkens skin moles and can make melanoma hard to detect Herald Sun Tanning peptides like melanotan are trending online, but they're not approved, not regulated, and illegal to advertise in Australia. When products haven't been properly tested, there's no way to know what's actually 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 Dangerous' tanning products promoted by influencers