Topical metformin 15% gel versus dapsone 5% gel in the treatment of acne vulgaris: a split face study

Acne vulgaris (AV) is a prevalent dermatological condition with multifactorial pathogenesis, including hormonal, microbial, and inflammatory components. Although topical treatments remain first-line therapy for mild to moderate cases, limitations such as antibiotic resistance and adverse effects necessitate alternative options. This study aimed to evaluate and compare the clinical efficacy and safety of 15% topical metformin gel versus 5% topical dapsone gel in the management of AV using a split-face design. A single-blind, interventional, split-face study was conducted on 50 patients with AV. Each participant applied metformin 15% gel to one side of the face and dapsone 5% gel to the other side twice daily for 12 weeks, with a follow-up at week 16. Acne severity was assessed using the Global Acne Grading System (GAGS) at baseline and at regular intervals. Side effects and demographic correlations were also analyzed. Both agents significantly reduced GAGS scores over time. Dapsone showed superior efficacy at the 16-week follow-up, with a more sustained reduction in acne lesions. Side effects were minimal and comparable between groups. Younger patients showed better response, particularly to dapsone. Topical metformin and dapsone are both effective and well-tolerated treatments for AV. Dapsone demonstrated a slightly greater long-term benefit. Larger, multicenter trials are recommended to confirm these findings and explore combination regimens.

Graphical abstract