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 Melanoma induction by ultraviolet A but not ultraviolet B radiation requires melanin pigment Nature Communications Melanotan II reverses memory impairment induced by a short term HF diet ScienceDirect Melanotan is not a tan. It's an unregulated peptide with real risk. As a dermatologist, here's the reality: It has been linked to new and changing moles including cases of JLE European Journal of Dermatology Eruptive naevi and darkening of pre existing naevi 24 h after a single mono dose injection of melanotan II