Melanotan II: Tanning, Sexual Health Benefits, & Safety Concerns 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 Melanotan II (Tan Jabs): Why They're Not Worth The Risk Melanotan II PERMANENTLY Darkened My Skin! Sun and Skin: From Burns to Melanoma, What Every Clinician Needs to Know and Share Changes in Oral Mucosa Associated with Melanotan II Injections: A Case Report