Man warns against 'dangerous' tanning injections after turning so dark he 'looked like Madge from Benidorm' and now has the freckled skin of a 60 year old 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 longer lasting than Melanotan II Wikipedia How Long Does It Take For Melanotan To Work? Melanotanassociated melanoma Paurobally 2011 British Journal of Dermatology Wiley Online Library