Systemic and Topical Metformin Versus Glycolic Acid Peel for the Treatment of Acanthosis Nigricans

Acanthosis nigricans (AN) is a common dermatologic condition associated with insulin resistance and obesity. Existing treatment options often provide inconsistent results. This randomized, single-blinded, parallel-group clinical trial was conducted to evaluate and compare the efficacy and safety of systemic metformin, topical metformin 30%, and 70% glycolic acid chemical peel in the treatment of patients with acanthosis nigricans. Fifty-four patients with clinically diagnosed acanthosis nigricans were randomly assigned to receive oral metformin, topical metformin 30%, or glycolic acid 70% chemical peel. Clinical efficacy was assessed using the Acanthosis Nigricans Area and Severity Index (ANASI), Global Aesthetic Improvement Scale (GAIS), dermoscopic evaluation, patient satisfaction, and safety outcomes. The study aimed to determine whether topical metformin provides efficacy comparable to systemic metformin while reducing treatment-related adverse effects.