Comparison of high-fluence, single-pass diode laser to low-fluence, multiple-pass diode laser for laser hair reduction with 18 months of follow up.

Laser hair removal is the most popular laser procedure in the United States (U.S.), yet there has not been a prospective study demonstrating long-term efficacy of diode laser hair removal beyond six months. A prospective, single-center, bilaterally paired, blinded, randomized comparison split leg study was carried out with 22 patients comparing high-fluence, single-pass diode laser to low-fluence, multiple-pass diode laser. Hair counts were done six and 18 months following five treatment sessions and were found to be comparable t90-94 percent hair reduction. Hair counts at six months following the fifth treatment were comparable to hair counts at 18 months, indicating that sixth-month hair counts can be considered indicative of long-term results. The low-fluence, multiple-pass in-motion technique was associated with significantly less pain compared to the high-fluence, single-pass technique. Multiple passes of a diode laser at low fluences but with high average power results in permanent hair removal with less discomfort and fewer adverse effects, especially in darker skin.