Comparison of Efficacy of Metformin Gel 30% vs Triple Combination Cream (Hydroquinone 4%, Flucinolone Acetonide 0.01%, Tretinoin 0.025%) in Treatment of Melasma in Tertiary Care Hospital Karachi.

This randomized, parallel-group clinical trial will be conducted at the Department of Dermatology, Jinnah Postgraduate Medical Centre (JPMC), Karachi, Pakistan, after approval from the Institutional Review Board/Ethics Committee of JPMC. Eligible patients presenting with clinically diagnosed melasma will be screened and enrolled after obtaining written informed consent.

Participants will be randomly assigned in a 1:1 ratio to one of two treatment arms using a computer-generated randomization sequence. Group A (active comparator) will receive topical triple combination cream containing hydroquinone 2%, tretinoin 0.025%, and fluocinolone acetonide 0.01%, applied once nightly to affected facial areas for 12 weeks. Group B (experimental) will receive topical metformin gel 30%, applied once nightly to melasma-affected areas for 12 weeks. All participants in both arms will be advised to apply broad-spectrum sunscreen (SPF ≥30) during daytime throughout the treatment period.

Melasma severity will be assessed using the Melasma Area and Severity Index (MASI) at baseline and during follow-up visits over the 12-week treatment period. The primary outcome will be the proportion of participants achieving at least a 50% reduction in total MASI score from baseline at week 12. Safety and tolerability will be monitored throughout the study by documenting adverse effects reported by participants or observed on clinical examination.