Topical Metformin Versus Triple Regimen for Epidermal Melasma

Melasma is a common skin condition that causes dark brown patches, mainly on sun-exposed areas of the face. It is often persistent, may recur after treatment, and can affect a person's quality of life. The standard topical triple regimen used for melasma contains hydroquinone, tretinoin, and fluocinolone acetonide. Although effective, prolonged use may cause adverse effects such as redness, burning, peeling, telangiectasia, and steroid-related skin changes. Topical metformin has recently been investigated as a possible alternative treatment because it may reduce skin pigmentation with relatively few side effects.

This randomized clinical trial will compare the efficacy of topical 30% metformin cream with a topical triple regimen in adults with epidermal melasma. A total of 104 participants aged 18-50 years will be enrolled, with 52 participants assigned to each treatment group. Group A will receive topical 30% metformin, while Group B will receive a triple regimen containing 2% hydroquinone, 0.05% tretinoin, and 0.01% fluocinolone acetonide. Participants will apply the assigned treatment once daily at night for eight consecutive weeks. All participants will also be advised to use SPF 50 or higher sunscreen in the morning.

Treatment efficacy will be assessed by comparing the modified Melasma Area and Severity Index score at baseline and after eight weeks. Treatment will be considered effective when the participant achieves at least a 25% reduction in the modified MASI score from baseline. The findings may help identify a more effective and acceptable topical treatment option for patients with epidermal melasma