Melanotan What It Is and Its Relation to Skin Cancer One month. Minimal sun. Real results. These results are after a 10 day loading phase and just 1 month of our Barbie Peptide (Melanotan II) with little to no sun exposure. Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn 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 A Sun Kissed Look, and a Confident You. The Barbie Peptide? Why Melanotan 2 Has Become One of the Most Talked About Compounds in the Peptide World