A Randomized Controlled Study - Comparing the Safety and Efficacy of Topical 5% Methimazole Versus Topical 4% Hydroquinone in the Treatment of Melasma

Abstract

Objective: This study aimed to compare the efficacy and safety of topical 5% methimazole versus 4% hydroquinone in the treatment of melasma.

Methods: A total of 50 participants with diagnosed melasma were randomized into two groups: one receiving 5% methimazole cream and the other 4% hydroquinone cream. Treatment was applied nightly for 8 weeks, followed by a 4-week observation period without active treatment. The primary outcome was the change in the Melasma Area and Severity Index (MASI) score, assessed at baseline, 4th, 8th, and 12th weeks.

Results: Both treatments resulted in a significant reduction in MASI scores at the 8th week, with the hydroquinone group showing a greater initial decrease (p < 0.001). However, this group also experienced a higher relapse rate post-treatment, indicating a potential for greater recurrence once treatment ceased. The methimazole group showed a consistent reduction with a lower relapse rate, suggesting more stable long-term results.

Conclusions: Both 5% methimazole and 4% hydroquinone are effective in the treatment of melasma, yet methimazole may offer advantages in terms of sustained improvement and lower relapse rates post-treatment. These findings support further investigation into methimazole as a potentially preferable option for long-term melasma management.