The Growth of Human Scalp Hair Mediated by Visible Red Light Laser and LED Sources in Males

Background and ObjectivesLow level laser therapy (LLLT) has been used to promote hair growth. A double-blind randomized controlled trial was undertaken to define the safety and physiologic effects of LLLT on males with androgenic alopecia. MethodsForty-four males (18-48 yo, Fitzpatrick I-IV, Hamilton-Norwood IIa-V) were recruited. A transition zone scalp site was selected; hairs were trimmed to 3mm height; the area was tattooed and photographed. The active group received a TOPHAT655 unit containing 21, 5mW lasers (6555nm), and 30 LEDS (65520nm), in a bicycle-helmet like apparatus. The placebo group unit appeared identical, containing incandescent red lights. Patients treated at home every other dayx16 weeks (60 treatments, 67.3J/cm(2) irradiance/25minute treatment), with follow up and photography at 16 weeks. A masked 2.85cm(2) photographic area was evaluated by another blinded investigator. The primary endpoint was the percent increase in hair counts from baseline. ResultsForty-one patients completed the study (22 active, 19 placebo). No adverse events or side effects were reported. Baseline hair counts were 162.7 +/- 95.9 (N=22) in placebo and 142.0 +/- 73.0 (N=22) and active groups respectively (P=0.426). Post Treatment hair counts were 162.4 +/- 62.5 (N=19) and 228.7 +/- 102.8 (N=22), respectively (P=0.0161). A 39% percent hair increase was demonstrated (28.4 +/- 46.2 placebo, N=19; 67.2 +/- 33.4, active, N=22) (P=0.001) Deleting one placebo group subject with a very high baseline count and a very large decrease, resulted in baseline hair counts of 151.1 +/- 81.0 (N=21) and 142.0 +/- 73.0 (N=22), respectively (P=0.680). Post treatment hair counts were 158.2 +/- 61.5 (N=18) and 228.7 +/- 102.8 (N=22) (P=0.011), resulting in a 35% percent increase in hair growth (32.3 +/- 44.2, placebo, N=18; 67.2 +/- 33.4, active, N=22) (P=0.003). ConclusionsLLLT of the scalp at 655nm significantly improved hair counts in males with androgenetic alopecia. Lasers Surg. Med. 45:487-495, 2013. (c) 2013 Wiley Periodicals, Inc.