NEW YORK (Reuters Health) - Combining two different types of lasers to remove unwanted hair is no more effective than using either laser alone, and may result in more adverse effects, new research shows.
Laser hair removal, first described in 1996, works by destroying the hair follicle, Dr. Alireza Firooz, of the Tehran University of Medical Sciences in Iran, and colleagues explain in the Archives of Dermatology.
Various wavelengths of laser light are in use, they add, while some "controversial" ideas have been put forth about the effectiveness of using more than one type of laser in combination.
To look into this issue, Firooz's team compared the alexandrite laser and the Nd:YAG laser, individually and in combination, for removing leg hair in 20 people, 15 of whom completed the study.
Each person received four different treatments in different areas: the Nd:YAG; the alexandrite laser in two different "spot sizes"; and the Nd:YAG plus the alexandrite laser. All areas were treated four times, eight weeks apart.
After 18 months, hair reduction was similar for all four approaches, ranging from 73.6 percent to 84.3 percent.
However, the skin areas treated with the laser combination were significantly more likely to have been darkened, or hyperpigmented, by the treatments, and these areas were also significantly more painful after treatment.
"We discovered that the combination treatment will not add any more significant benefit and, unfortunately, it will cause more adverse effects," Firooz and colleagues conclude. However, both types of laser treatment used alone "have long-term persistent efficacy in hair reduction with acceptable and transient adverse effects."