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.