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 That quick tan injection is NOT worth the risk., Melanotan peptide injections stimulate pigment cells, and its use has been linked to rapid changes in moles, including the potentially fatal skin Melanotan II Skin Pigmentation & Libido Is Melanotan the New Solarium for a Perfect Tan?