Table 1. Data of Clinical Studies of Low Level Laser Therapy for Hair Loss

First Author (Year)	Intervention		Main Outcomes	Results
	Experimental Group(Ex G)	Control group(Con G)
Faghihi G9) (2018)	n = 23A : minoxidil 5% 2 times/dayB : Low level laser 785 ㎚, 10-50 ㎽ 20min/day, 2-3times/week × 6 months	n = 22A : minoxidil 5% 2 times/dayC : Placebo light 20min/day, 2-3times/week × 6 months	ㆍhair density(count/cm2)ㆍhair diameter(㎚)ㆍside-effects	ㆍhair density Ex G : 14.9 ± 2.8 → 25.9 ± 2.5 Con G : 14.8 ± 2.9 → 22.2 ± 3.8ㆍhair diameter(Change to ㎛) Ex G : 50 ± 6 → 73 ± 6 Con G : 51 ± 11 → 67 ± 15ㆍside-effects : no significant differences
Mai-Yi Fan S10)(2018)	n = 100A : LED + Laser- LED : 660 ± 5 ㎚, 22 ㎽- Low level laser 650 ± 10 ㎚, 4.6 ㎽30 min/day3 times/week × 24 weeks	n = 100B : Placebo light 30 min/day 3 times/week × 24 weeks	ㆍhair density change (count/cm2)ㆍhair diameter change (㎛)ㆍside-effects	ㆍhair density change Ex G : Δ 6.7 ± 11.9 Con G : Δ -1.1 ± 11.9ㆍhair diameter change Ex G : Δ 2.3 ± 4.3 Con G : Δ -1.3 ± 3.5ㆍside-effects : no adverse even
Suchonwanit P11)(2018)	n = 19A : Low-level laser(n=19) 660 ± 10 ㎚, 5 ㎽ 20 min/day 3 times/week × 24 weeks	n = 17B : Placebo light 20 min/day 3 times/week × 24 weeks	ㆍhair density change (count/cm2)ㆍhair diameter change (μm)	ㆍhair density change Ex G : Δ 10.21 ± 3.25 Con G : Δ 3.95 ± 1.32ㆍhair diameter change Ex G : Δ 6.11 ± 2.15 Con G : Δ 3.76 ± 1.24
Esmat SM12)(2017)	n = 15A : minoxidil 5% 2 times/dayB : Laser + LED - LED : 660 - 5 ㎚ - Low level laser 655 ㎚, <5 ㎽ 25min/day, every other day × 4 months	Control Group 1(n = 15)A : minoxidil 5% 2 times/day × 4 monthsControl Group 2(n = 15)B : Laser + LED - LED : 660 - 5 ㎚ - Low level laser 655 ㎚, <5 ㎽ 25min/day, every other day × 4 months	ㆍhair density(count/cm2)ㆍhair diameter(㎚)ㆍside-effects	ㆍhair density Ex G : 144.2±20.42 → 207.2±12.97 Con G1 : 141.93±19.43 → 191.53±18.23 Con G2 : 145.47±20.37 → 195.53±14.71ㆍhair diameter(Change to ㎛) Ex G : 50 ± 16 → 64 ± 29 Con G1 : 48 ± 16 → 50 ± 16 Con G2 : 47 ± 13 → 63 ± 23ㆍside-effects : no major side effects
Friedman S13)(2017)	n = 19 A : Low-level laser 650 ㎚, 5 ㎽, 20 min/day, every other day × 17 weeks(60 treatment)	n = 21B : Placebo light 20 min/day, every other day × 17 weeks(60 treatment)	ㆍhair density change (count/cm2)ㆍside-effects	ㆍhair density change Ex G : Δ89.9±63.3 Con G : Δ18.5±24.4ㆍside-effects : no side effects or adverse events
Lanzafame RJ14)(2014)	n = 24A : LED + Laser - LED : 655 ± 20 ㎚ - Low level laser 655 ± 5 ㎚, 5 ㎽ 25 min, 2 times/day × 16 weeks	n = 18B : Placebo light 25 min, 2 times/day × 16 weeks	ㆍhair density change (count/cm2)ㆍside-effects	ㆍhair density Ex G : Δ100.3±53.4 Con G : Δ23.9±30.1ㆍside-effects : no side effects
Lanzafame RJ15)(2013)	n = 22A : LED + Laser - LED : 655 ± 20 ㎚ - Low level laser 655 ± 5 ㎚, 5 ㎽ 25 min, 2 times/day × 16 weeks	n = 19B : Placebo light 25 min, 2 times/day × 16 weeks	ㆍhair density change (count/cm2)ㆍside-effects	ㆍhair density Ex G : Δ67.2 ± 33.4 Con G : Δ28.4 ± 46.2ㆍside-effects : no side effects
Leavitt M16)(2009)	n = 71A : lower level laser 655㎚, Power unknown 15 min/day, 3 times/week × 26 weeks(6 months)	n = 39B : Placebo light 15 min/day, 3 times/week × 26 weeks(6 months)	ㆍhair density change (count/cm2)ㆍside-effects	ㆍhair density Ex G : Δ17.3 ± 11.9 Con G : Δ-8.9 ± 11.7ㆍside-effects : no serious adverse effects