Peptides are having a moment, but not all of them are harmless., One thats getting a lot of attention right now? Melanotan II., Its being used to achieve a tan from the inside, but what it Melanotan What It Is and Its Relation to Skin Cancer MELANOTAN 2 (10ml 20mg) peptide to stimulate melanin synthesis. Melanotan II Skin Pigmentation & Libido Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn