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 (Tan Jabs): Why They're Not Worth The Risk Tanning from the inside out = Highly Dangerous and Illegal!, Many products advertised on social media platforms promising a tan from the inside out or a tan without sun such as injectable Warning issued over increased use of 'Barbie drug' Dangerous' tanning products promoted by influencers