RESUMO
BACKGROUND: Melasma is a common pigmentary condition that affects the patients' quality of life and all the prescribed treatment options till now are not satisfactory, especially in dark-skinned patients. OBJECTIVE: To evaluate the efficacy and safety of systemic metformin (1,000 mg and 500 mg) combined with trichloroacetic acid (TCA) peeling versus TCA alone in the treatment of melasma. PATIENTS AND METHODS: The study included 60 melasma patients divided into 3 groups: Group A received systemic metformin (1000 mg/d), Group B received systemic metformin (500 mg/d) and Group C received placebo. The 3 treatment groups were treated by TCA 25% over the whole face bimonthly for a total of 6 sessions. Melasma area and severity index (MASI), and Melasma impact Quality of life Scale (MELASQOL) were used to assess the outcome. RESULTS: There was a statistically significant decrease in the MASI, and the MELASQOL in the 3 studied groups after treatment with significantly better improvement in Group (A) than Group (C) ( p = .045). CONCLUSION: Systemic metformin is a safe and promising therapeutic option for treating melasma.