BACKGROUND AND OBJECTIVES:

Low level laser (light) therapy (LLLT) has been demonstrated to promote hair growth in males. A double-blind randomized controlled trial was undertaken to define the safety and physiologic effects of LLLT on females with androgenic alopecia.

METHODS:

Forty-seven females (18-60 years old, Fitzpatrick I-IV, and Ludwig-Savin Baldness Scale I-2, I-3, I-4, II-1, II-2 baldness patterns) were recruited. A transition zone scalp site was selected; hairs were trimmed to 3?mm height; the area was tattooed and photographed. The active group received a “TOPHAT655” unit containing 21, 5?mW diode lasers (655?±?5?nm) and 30 LEDS (655?±?20?nm), in a bicycle-helmet like apparatus. The placebo group unit appeared identical, containing incandescent red lights. Patients treated at home every other day?×?16 weeks (60 treatments, 67?J/cm(2) irradiance/25?minute treatment, 2.9?J dose), with follow up and photography at 16 weeks. A masked 2.85?cm(2) photographic area was evaluated by another blinded investigator. The primary endpoint was the percent increase in hair counts from baseline.

RESULTS:

Forty-two patients completed the study (24 active, 18 sham). No adverse events or side effects were reported. Baseline hair counts were 228.2?±?133.4 (N?=?18) in the sham and 209.6?±?118.5 (N?=?24) in the active group (P?=?0.642). Post Treatment hair counts were 252.1?±?143.3 (N?=?18) in the sham group and 309.9?±?166.6 (N?=?24) in the active group (P?=?0.235). The change in hair counts over baseline was 23.9?±?30.1 (N?=?18) in the sham group and 100.3?±?53.4 (N?=?24) in the active group (P?<?0.0001). The percent hair increase over the duration of the study was 11.05?±?48.30 (N?=?18) for the sham group and 48.07?±?17.61 (N?=?24) for the active group (P?<?0.001). This demonstrates a 37% increase in hair growth in the active treatment group as compared to the placebo group.

CONCLUSIONS:

LLLT of the scalp at 655?nm significantly improved hair counts in women with androgenetic alopecia at a rate similar to that observed in males using the same parameters.

© 2014 The Authors. Lasers in Surgery and Medicine Published by Wiley Periodicals, Inc.