The Effect of Topical Glycerol Trinitrate on Laser-Aided Facial Hair Removal: A Triple-Blinded Randomized Clinical Trial.

Abstract

Our purpose in this study was to assess the effect of topical glyceryl trinitrate on the efficacy of long-term white hair removal aided by laser therapy in hirsute women. Nitric oxide (NO) induces vasorelaxation and augmented perfusion when released from endothelial cells or from an alternatively provided exogenous source. Separately, vascular endothelial growth factor (VEGF)-mediated angiogenesis during the anagen phase, the phase most susceptible to laser elimination, and modulation of VEGF by NO, has been discussed previously, but there are limited data regarding an efficient method for long-term white hair removal. We conducted a triple-blinded randomized controlled clinical trial. Hirsute women with excess facial hair without a known allergy to nitroglycerin derivatives were recruited, and randomly allocated to receive either premedication with 2 g glycerol trinitrate 3 days before the laser sessions once a day, or placebo. All the participants underwent six laser sessions with 1-month intervals. Baseline hair numbers were counted before, 3, 6, and 12 months after the first session. Data were analyzed with repeated measures ANOVA test. A total of 83 patients were enrolled in control (43) and case (40) groups. The trends for hair reduction in both studied groups were significant (p < 0.001), but there were no significant differences between the case and control groups during the study period. According to our findings, all patients, regardless of whether or not they used trinitrate, had significant success with hair removal. This study could not differentiate hair removal efficacy between the study groups. Studies with other laser types and larger sample sizes are suggested to investigate the effect of NO on hair production.