LLLT Part 3: Critically Assessing Recent Published LLLT Device Trials: Limitations, Recommendations, and Conclusions

In 2015, Dr. Sharon A. Keene critically evaluated trials of Low-Level Laser Therapy (LLLT) devices for hair growth, focusing on four randomized controlled trials from 2013-2014. The trials, which involved helmets with multiple diode lasers and a laser comb, had several limitations including small sample sizes, lack of control groups, short study durations, and failure to address how the presence of hair could affect light therapy application. The studies also lacked long-term follow-up and did not address dosing or how duration and frequency of treatment were determined. While each study reported varying degrees of positive results, the review concluded that more rigorous and well-designed studies were needed to confirm the effectiveness of LLLT devices. The document recommended future research to identify optimal wavelength and adjustable dosing regimens, and to create a device that can bypass hair and skin to uniformly reach cellular targets.