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.

Inclusion Criteria: * Clinical diagnosis of acanthosis nigricans. Age 11 years or older. Male or female participants. Willingness and ability to comply with the study protocol and provide written informed consent (or assent with parental/guardian consent for minors, as applicable). Exclusion Criteria: * Pregnancy or lactation. History of keloid formation or post-peel hyperpigmentation. Active skin infection. Malignant acanthosis nigricans. Use of other treatments for acanthosis nigricans within the previous 3 months.