Comparison of Long-Pulsed Alexandrite and Nd:YAG Lasers, Individually and in Combination, for Leg Hair Reduction: An Assessor-Blinded, Randomized Trial With 18 Months of Follow-up

Objective To compare the long-term effectiveness and safety of long-pulsed Nd:YAG and alexandrite lasers, individually and in combination, in long-term leg hair reduction. Design Randomized, single-center, within-participant, investigator-blinded, active-controlled clinical trial. Setting Private skin laser center. Participants Twenty individuals aged 16 to 50 years with skin phototypes III and IV. Interventions The medial and lateral sides of each participant's legs were randomly assigned to receive 1 of the following laser treatments: (1) long-pulsed 1064-nm Nd:YAG laser (12-mm spot size); (2) long-pulsed 755-nm alexandrite laser (12-mm spot size); (3) long-pulsed 755-nm alexandrite laser (18-mm spot size); and (4) a combination of long-pulsed 1064-nm Nd:YAG laser and long-pulsed 755-nm alexandrite laser (treatments 1 and 2). Identified areas were treated for a total of 4 sessions at 8-week intervals. Main Outcome Measures Hair reduction from baseline based on hair counting with digital photography by 2 blinded assessors, 8 and 18 months after the last treatment session. Results Fifteen participants completed the trial. The mean (SD) hair reduction 18 months after the last treatment, as measured by the assessors from digital photographs, were 75.9% (19.0%) for the 12-mm spot size alexandrite laser, 84.3% (12.4%) for the 18-mm spot size alexandrite laser, 73.6% (11.4%) for the Nd:YAG laser, and 77.8% (15.9%) for the combination therapy (analysis of variance, P  > .05). The incidence of adverse effects (hyperpigmentation) and pain severity were significantly greater in areas that received combination therapy ( P  = .001). Conclusions After 18 months of follow-up, alexandrite and Nd:YAG lasers were efficacious for leg hair removal. Combination therapy did not have any additional benefit and caused more adverse effects.