41546 Efficacy and safety of topical metformin gel in the treatment of acne vulgaris, a split face, placebo-controlled study

Background: Acne vulgaris (AV) is a widely common disorder that negatively affects the patient's quality of life (1). Metformin is a relatively safe, cheap, and well tolerated systemic drug that is widely prescribed in the treatment of Diabetes Mellitus (2). Systemic metformin has demonstrated promising results in treating acne (3), while topically it was studied for skin disorders including melasma (4) and recalcitrant central centrifugal cicatricial alopecia (5) in humans as well as treating melanoma and wound healing in experimental animals (6). Objectives: to study the efficacy and safety of topical metformin 30% in treating acne compared to placebo. Methods: twenty‐seven female AV patients were asked to blindly apply metformin and placebo gels to either side of the face for 12 weeks. AV lesion count was performed at baseline, every 4 weeks during treatment and 4 weeks after stoppage of treatment. Results: twenty one patients completed the study. At the end of the treatment period, the treated side showed significant improvement of comedones, papules and nodules but not pustules, however, except for comedones, the improvement of inflammatory lesions declined significantly after stopping treatment. No side effects were reported on either side of the face. Limitations: The limited number of patients studied and the limited follow up period. The metformin effect was not studied on cellular and molecular levels. Conclusions: Topical metformin nanoemulsion gel can be a promising safe and effective treatment of AV. The effect of metformin on the different patho‐mechanisms involved in AV may vary in onset and potential.