Melanotan II Injections Linked to Oral Mucosa Pigmentation in Case Study

Melanotan II (MT2) is a synthetic peptide analogue of alpha-melanocyte-stimulating hormone (α-MSH) often used illicitly for its tanning effects. It works by stimulating melanocytes to produce melanin, leading to skin darkening. While its effects on skin pigmentation are well-known, less is understood about its potential side effects on other tissues, particularly the oral mucosa. This case report specifically addresses the occurrence and characteristics of oral mucosal changes associated with Melanotan II use.

The patient presented with multiple dark brown to black macules (flat spots) ranging from 2 mm to 8 mm in diameter, primarily located on the buccal mucosa (inner cheek lining) and gingiva (gums). These lesions developed over a period of 2-3 weeks. Histopathological examination of a biopsy confirmed a significant increase in melanin deposition within the basal layer of the oral epithelium, consistent with drug-induced hyperpigmentation. Cessation of Melanotan II led to a partial but significant regression of the oral lesions, with over 60% reduction in pigmentation and size observed within 6 months. While complete resolution was not achieved by the 1-year follow-up, the remaining lesions were stable and notably lighter, indicating a direct link between Melanotan II use and the observed oral changes.