Ch22: Pigmentations of the Oral Mucosa and Facial Skin Oral melanotic macule Stock Image C067 2476 Science Photo Library Can You Use Melanotan Long Term? Any information on dark spots on the bottom lip? 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