Comparison of the Efficacy of Kligman's Formula Combined With 30% Topical Metformin Versus Kligman's Formula Alone in the Treatment of Melasma Publisher

Summary: Does adding metformin improve melasma creams? A 31-patient trial found similar overall results with or without topical metformin; possible pigment stability gains need study. #Melasma #SkinCare

Iraji F ; Mokhtari F ; Kassab Z ; Seyedyousefi S ; Varshosaz J
Source: Journal of Cosmetic Dermatology Published:2026

Abstract

Background: Melasma is a common hyperpigmentation disorder primarily affecting women, influenced by ultraviolet exposure, hormones, and genetics. Kligman's formula is a first-line therapy, but emerging evidence suggests that topical metformin, an antidiabetic with antimelanogenic effects, may enhance treatment outcomes. The objective of this study is to compare the efficacy and safety of Kligman's formula with and without 30% topical metformin in bilateral facial melasma. Methods: In this randomized, double-blind, split-face clinical trial, 31 patients with symmetrical facial melasma applied Cream A (Kligman's formula + 30% metformin) to one side and Cream B (Kligman's formula alone) to the other for 2 months. Outcomes included MASI scores, repigmentation grading, patient satisfaction via Visual Analog Scale (VAS), and side effect profiles assessed at baseline, post-treatment, and 2 months after discontinuation. Results: Both treatments significantly reduced pigmentation and improved homogeneity. Cream B showed a slightly greater reduction in darkness, while Cream A led to more stable repigmentation and fewer cases of post-inflammatory hyperpigmentation. No significant differences were found between post-treatment and follow-up scores. VAS scores indicated high patient satisfaction across both groups. Conclusion: Adding 30% topical metformin to Kligman's formula is safe and comparably effective in melasma treatment, offering potential benefits in pigment stability and reduced PIH. Although differences were not statistically significant, clinical trends support further investigation through larger, long-term studies. Trial Registration: ClinicalTrials.gov identifier: IRCT20150706023081N2. © 2026 The Author(s). Journal of Cosmetic Dermatology published by Wiley Periodicals LLC.