The Growth of Human Scalp Hair in Females Using Visible Red Light Laser and LED Sources. Lanzafame RJ, Blanche RR, Chiacchierini RP, Kazmirek ER, Sklar JA.
Background and Objectives: Low-Level 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.
Forty-Seven women between the ages of 18—60 with Fitzpatrick Skin Types I—IV and Ludwig— Savin Baldness Scale I-2—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” (iGrow unit) unit containing 21, 5 mW lasers (655 +/- 5 nm), and 30 LEDs (655 +/- 20 nm), in a bicycle-helmet like an apparatus. The placebo group unit appeared identical, containing incandescent red lights. Patients treated at home every other day ✕ 16 weeks (60 treatments, 67.3 J/cm(2) irradiance/ 25-minute treatment), 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.
Forty-two patients completed the study (24 actives, 18 shams). 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.
LLLT of the scalp at 655nm significantly improved hair counts in women with androgenetic alopecia at a rate similar to that observed in males using the same parameters.