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 The "Barbie Drug" Has a Dark Side Who's tan is reay for summer. This peptide can help. No, you don't need the 'Barbie drug' to tan, whatever TikTok says. Here's why melanotan II is so risky Melanotan II: Tanning, Sexual Health Benefits, & Safety Concerns