Laser Hair Removal: Comparison between Yag and Alexandrite
Alexandrite or Nd: YAG laser therapy is effective for leg hair removal, but combination therapy causes more adverse effects without additional benefit, according to the results of a randomized controlled, investigator-blinded trial reported in the October issue of Archives of Dermatology.
“Unwanted hair that potentially has profound effects on psychological well-being is an exceedingly common concern for men and women,” write Seyyed Masoud Davoudi, MD, from the Baqiyatallah University of Medical Sciences in Tehran, Iran, and colleagues. “Laser-assisted photo epilation or laser hair removal, as first reported in 1996, is accomplished through destruction of the follicular unit…. During the past decade, laser hair removal has become an accepted and popular means of achieving hair reduction.”
The goal of this study was to compare the long-term efficacy and safety of long-pulsed Nd: YAG and alexandrite lasers, both individually and in combination, for long-term reduction in leg hair.
At a private skin laser center, 20 participants aged 16 to 50 years with skin phototypes 3 and 4 were enrolled, and identified areas were treated for a total of 4 sessions at 8-week intervals. The medial and lateral sides of each participant’s legs were randomly assigned to 1 of the following therapies:
long-pulsed 1064-nm Nd: YAG laser with 12-mm spot size
long-pulsed 755-nm alexandrite laser with 12-mm spot size
long-pulsed 755-nm alexandrite laser with 18-mm spot size
a combination of long-pulsed 1064-nm Nd: YAG laser and long-pulsed 755-nm alexandrite laser (treatments 1 and 2)
The primary endpoint was hair reduction from baseline, based on hair counting by 2 blinded evaluators using digital photography 8 and 18 months after the last laser therapy session.
Among 15 participants who completed the trial, mean hair reduction 18 months after the last treatment was 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 combination treatment (P <.05 by analysis of variance).
Areas that received combination therapy had a significantly greater incidence of adverse effects — primarily hyperpigmentation — and pain severity (P = .001). Average pain severity was higher in areas treated with alexandrite laser than in those treated with the Nd: YAG laser, but pain severity was highest in areas treated with both lasers.
“After 18 months of follow-up, alexandrite and Nd: YAG lasers were efficacious for leg hair removal,” the study authors write. “Combination therapy did not have any additional benefit and caused more adverse effects.”
Limitations of this study include dropout rate of 25% and difficulties in the method of evaluating hair counts.
“Despite other studies showing more efficacy of the alexandrite rather than the Nd: YAG laser, our trial results showed no significant difference between them,” the authors conclude. “The use of alexandrite or Nd: YAG laser systems alone for at least four treatment sessions and with eight-week intervals have long-term persistent efficacy in hair reduction with acceptable and transient adverse effects.”
By Laurie Barclay, MD