Kim 2013.

Methods	This was a randomised, double‐blind, sham device‐controlled trial Setting Multicentre (2), Korea Date of study Unspecified (24‐week duration)
Participants	40 men and women (26 men, 14 women) Mean age (SD) = 43.9 years (12.2) in the low level light therapy group, 44.5 years (11.4) in the sham device group Inclusion criteria Diagnosis of androgenetic alopecia. Norwood‐Hamilton classification of III to VII for men or a Ludwig classification of I to III for women. Exclusion criteria Topical or systemic medications affecting hair growth, such as finasteride, cyclosporine, or minoxidil, within the past 6 months. Hair disorders other than AGA or systemic diseases that might affect the results. Randomised 40 participants were randomised (low level light therapy group = 20, sham group = 20) Withdrawals/losses to follow‐up There were 11/40 (27.5%) withdrawals/losses to follow‐up: 5/20 (25%) in the low‐level light therapy group, and 6/20 (30%) in the sham group Withdrawal of consent: low‐level light therapy group (0), sham group (2). Non adherence: low‐level light therapy group (5), sham group (4). Baseline data Duration hair loss (SD): low level light therapy group = 114.3 months (86.2), sham group = 100.55 months (84.8) Norwood‐Hamilton III: low level light therapy group = 6, sham group = 4. Norwood‐Hamilton IV: low level light therapy group = 2, sham group = 4.Norwood‐Hamilton V: low level light therapy group = 1, sham group = 3. Norwood‐Hamilton VI: low level light therapy group = 5, sham group = 1. Ludwig I: low level light therapy group = 5, sham group = 8. Ludwig II: low level light therapy group = 1, sham group = 0.
Interventions	Intervention Helmet‐type, home‐use low‐level light therapy device emitting wavelengths of 630, 650, and 660 nm for 18 minutes daily for 24 weeks. Comparator Sham device daily for 18 minutes for 24 weeks.
Outcomes	Assessments (3): at baseline, week 12, and week 24 Primary outcomes (as reported) Changes in hair density from baseline (phototrichogram, Folliscope, LeadM, Seoul, Republic of Korea).¹ Secondary outcomes (as reported) Changes in the hair shaft.¹ Global assessment of hair regrowth according to the participant and the investigator.¹ Subjective satisfaction.¹ Adverse events.¹ ¹Denotes outcomes prespecified for this review
Funding source	Quote (page 1177): "This study was supported by Won Technology, Daejeon, Republic of Korea."
Declaration of interest	Quote (page 1177): "The authors have indicated no significant interest with commercial supporters"
Notes	The trial did not stratify data by gender. We sent e‐mails to the PI, but received no reply. See Table 8
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote (page 1177): "randomized" and "We randomly assigned". Comment: the trial authors did not report the method used to generate the allocation sequence in sufficient detail to allow a clear assessment of whether it would produce comparable groups. After e‐mail communication: "coin throw method for the allocation" Comment: this was probably done.
Allocation concealment (selection bias)	Unclear risk	The trial did not report the method used to conceal the allocation sequence, that is to determine whether intervention allocations could have been foreseen in advance of, or during, enrolment. Comment: there was insufficient information to permit a clear judgement.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Quote (page 1177): "double‐blind" and "The sham device was identical in appearance and its regulator operated, although it emitted no light", and (page 1179) " they were totally blinded". Comment: we judged this as at an unclear risk of bias in view of the fact that the helmet did not emit light.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Quote (page 1177): "double‐blind", (page 1179 " the investigators in charge of efficacy assessment were totally blinded". Comment: both investigators and participants were outcome assessors. We judged this as at an unclear risk of bias as the helmet did not emit light and might have influenced the outcome assessment by the participants.
Incomplete outcome data (attrition bias) All outcomes	High risk	There were 11/40 (27.5%) withdrawals/losses to follow‐up: 5/20 in the low‐level light therapy group (25%), and 6/20 in the sham group (30%). The data analysis was per‐protocol. Comment: the large number of dropouts (26%), incomplete outcome data, and inappropriate analysis were potential sources of bias.
Selective reporting (reporting bias)	Low risk	The protocol for the study was unavailable, but the trial appeared to report the prespecified outcomes and those mentioned in the methods section. Comment: we judged this as at a low risk of bias.
Other bias	Low risk	Comment: the study appeared to be free of other forms of bias.