Amber LED photobiomodulation versus tranexamic acid for the treatment of melasma: randomized controlled double-blind pilot trial.

PURPOSE: This study aimed to evaluate the efficacy of amber photobiomodulation (PBM) compared to topical tranexamic acid (TXA) for the treatment of melasma.

METHODS

In a non-inferiority randomized controlled trial, 21 women were randomized to either active PBM with placebo cream (n = 10) or sham PBM with 5% liposomal TXA cream (n = 11) for 12 weeks. A noninferiority study was chosen based on the hypothesis that PBM could offer comparable efficacy to TXA with fewer adverse effects. The primary outcome was the Melasma Area and Severity Index (MASI). Secondary outcomes included corneomelametry, Physician's Global Assessment (PGA), quality of life measured by the MELASQoL questionnaire, and adverse events.

RESULTS

No significant differences were observed in the MASI or PGA scores, within or between groups. However, the study was underpowered (51% power) due to early termination and is thus considered a pilot. A transient increase in pigmentation intensity was observed in the TXA groups at week six. Despite the lack of clinical improvement, both groups sustained improvements in quality of life. The adverse events were mild, with PBM associated with warmth and TXA with a burning sensation. The absence of MASI reduction can be attributed to the elevated environmental temperatures during the study period, consistently above historical averages. In addition, both PBM and TXA may have limited efficacy in cases of chronic or dermal melasma.

CONCLUSION

Although no significant clinical changes were detected in MASI or PGA, both treatments improved the quality of life, highlighting the importance of patient-reported outcomes. Given the small sample size and potential environmental confounders-particularly elevated temperatures during the study period-definitive conclusions about treatment efficacy cannot be drawn. Future studies should consider optimized protocols and/or combination therapies.

TRIAL REGISTRATION: Clinical Trials No. NCT05326997, April 14th 2022.