Efficacy and Safety of Metformin for Melasma Treatment: A Systematic Review and Meta-Analysis

This systematic review and meta-analysis assessed the efficacy and safety of topical metformin for melasma treatment, analyzing three randomized controlled trials with 140 participants from Iran, India, and Egypt. The study found that 15% metformin cream significantly reduced the Melasma Area and Severity Index (MASI) score compared to placebo after 12 weeks, with higher patient satisfaction. However, 30% metformin was not significantly different from the standard triple combination cream (TCC) in reducing MASI scores or improving patient satisfaction after 8 weeks. Safety analysis showed fewer adverse effects with metformin compared to TCC, though not statistically significant. Despite metformin's potential as a melasma treatment with a favorable safety profile, the study's conclusions are limited by a small sample size, high bias risk, and short follow-up periods, indicating a need for further research with larger, well-designed trials.