Safety and efficacy of low-fluence, high-repetition rate versus high-fluence, low-repetition rate 810-nm diode laser for permanent hair removal--a split-face comparison study.

BACKGROUND This study was designed to evaluate the hypothesis that low-level fluences done repetitively on a hair follicle will produce permanent hair removal with less discomfort and fewer side effects than a single high-fluence pulse. OBJECTIVE To compare the safety and efficacy of a low-fluence, high-repetition rate versus a high-fluence, low-repetition rate 810-nm diode laser for permanent hair reduction in patients with facial hirsutism. METHODS Forty-two female patients with confirmed polycystic ovaries by ultrasonography with facial hirsutism were subjected to the low-fluence, high-repetition Soprano® XL laser in SHR mode and the LightSheer™ laser on each side of the face using preset parameters once a month for six sessions. Hair counts were done at the end of the sixth session using a 'Hi Quality Hair Analysis Program System' and the pain score was recorded by a visual analog scale. RESULTS The overall median reduction of hair was 90.5% with the Soprano XL and 85% with the LightSheer, with a standard deviation of 7 and 8.5 respectively. DISCUSSION This new technology, with low fluence and high repetition, showed a statistically insignificant increase in hair reduction compared to the LightSheer, but did show a significant reduction in hair thickness and a low pain score.