Based upon the thermal relaxation time (TRT) of the hair follicle (10-50 ms), most lasers and light devices use relatively long pulse widths for hair removal. The study by a group of medical practitioners headed by Dr. Khalil A. Khatri of the Skin & Laser Surgery Center of New England, MA was conducted to evaluate a shorter pulsed, 0.65 ms Nd:YAG laser for hair removal.

One half of each axilla of six female participants was treated and the other half was monitored as a control. The treatment sites were treated with a fluence of either 21 J/cm2 or 36 J/cm2 using an Nd:YAG laser with a wavelength of 1064 nm and a pulse duration of 0.65 ms. A manual hair count was done before treatment and at each follow-up visit.

Results:

Four months after four monthly treatments, the hair reduction was graded as 5 (75-100% reduction) on the high fluence side and 4 on the low fluence side (50-75% reduction) by individuals and investigators. The average hair count 4 months after four treatments in the sites treated with a high fluence went from 114 to 28 (76% reduction) and in the low fluence areas from 135 to 38 (72% reduction).

Conclusion:

This well-controlled study shows that a 0.65 ms Nd:YAG laser is effective and safe for hair removal with significantly lower level of pain.

 

Published in:  Journal of Cosmetic and Laser Therapy on 06 February 2009