The use of low-level light therapy in the treatment of androgenetic alopecia and female pattern hair loss.

Androgenetic alopecia (AGA) or female pattern hair loss (FPHL) is the most common form of hair loss in men and women. Despite its common occurrence, our understanding of the etiology of AGA and FPHL remains incomplete. As such, traditional therapies demonstrate modest efficacies and new therapies continue to be sought. Low-level light therapy (LLLT) is a relatively new technique used to promote hair growth in both men and women with AGA and FPHL. Currently, there exist several LLLT devices marketed for the treatment of alopecia, which claim to stimulate hair growth; yet marketing these devices only requires that safety, not efficacy, be established. A handful of studies have since investigated the efficacy of LLLT for alopecia with mixed results. These studies suffered from power, confounding and analysis issues which resulted in a high risk of bias in LLLT studies. Due to the paucity of well-conducted randomized controlled trials, the efficacy of LLLT devices remains unclear. Randomized controlled trials of LLLT conducted and reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement would greatly increase the credibility of the evidence and clarify the ambiguity of the effectiveness of LLLT in the treatment of AGA and FPHL.