No improvement in male-pattern hair loss using laser hair-comb therapy: a 6-month, half-head, assessor-blinded investigation in two men

A study was conducted on two healthy men with male-pattern hair loss (MPHL) to investigate the efficacy of laser hair-comb therapy. The laser comb was used on one side of the head for 7.5 minutes for 3 days each week for 26 weeks. The assessors were blinded to the treated sites. The study found no change in any hair variable between the treated and untreated sides in either subject. There was, however, an unexpected seasonal change in both subjects, with an increase in the anagen percentage and the number of hairs > 30 mm in length per cm², and a corresponding decrease in the number of hairs < 40 mm in length per cm² occurring in both sites. The study concluded that despite widespread acclaim on the internet and in the lay press for laser-generated hair growth in MPHL, many questions remain and further investigation is needed before laser hair-growth therapy can be taken seriously or advocated for MPHL.