This randomised controlled trial aims to compare the efficacy of topical metformin (30%) and topical tranexamic acid (3%) in the treatment of melasma using reduction in the Melasma Area and Severity Index (MASI) score over 12 weeks. Melasma is a common hyperpigmentation disorder with significant cosmetic and psychological impact, and current treatments often have limitations. Both metformin and tranexamic acid have shown promising depigmenting effects through different mechanisms. A total of 70 patients will be enrolled and randomly divided into two groups. Participants will apply the assigned treatment once daily along with sunscreen and will be assessed at baseline and at 4, 8, and 12 weeks. The primary outcome is MASI score reduction, while secondary outcomes include patient-reported improvement and safety. This study seeks to provide comparative evidence for safer and more effective treatment options for melasma management.