TOPICAL 0.5% MELATONIN CREAM VERSUS 3% TRANEXAMIC ACID CREAM FOR MELASMA: A RANDOMIZED DOUBLE-BLIND SPLIT-FACE STUDY

Abstract

Melasma is a chronic acquired hyperpigmentation disorder for which safe, sustained treatment remains challenging. This study compared the efficacy and safety of topical 0.5% melatonin cream with topical 3% tranexamic acid cream. In this prospective, randomized, double-blind, intra-individual split-face study, 20 adults with melasma were enrolled and 18 completed 12 weeks of treatment. Participants applied melatonin to one randomized hemiface and tranexamic acid to the contralateral hemiface twice daily; all used broad-spectrum sunscreen. Hemifacial modified Melasma Area and Severity Index (mMASI) scores and Mexameter melanin indices were assessed at baseline and Weeks 4, 8, and 12. Satisfaction and adverse effects were also evaluated. Mean hemifacial mMASI decreased from 3.11 to 2.73 with melatonin and from 3.11 to 2.51 with tranexamic acid (within-treatment p < 0.001 for both). Mean melanin index decreased from 254.8 to 242.2 and 236.3, respectively (within-treatment p < 0.001 for both). Between-treatment differences at individual visits were not statistically significant. Satisfaction scores of 4 or 5 (ranging from 1-lowest satisfaction to 5-highest satisfaction) were reported for 11 of 18 melatonin-treated sides and 12 of 18 tranexamic acid-treated sides (p = 1.000). Both preparations were well tolerated, with no moderate or severe adverse events. Topical 0.5% melatonin and 3% tranexamic acid both improved melasma over 12 weeks. Since there was no statistically significant difference in efficacy between the two creams, melatonin may represent a well-tolerated alternative deserving further evaluation in larger trials.