Hair growth / androgenetic alopecia
Low-level laser therapy for androgenetic alopecia systematic review and meta-analysis
Liu KH, Liu D, Chen YT, et al. Lasers in Medical Science. 2019.
A meta-analysis of adult androgenetic alopecia trials found increased hair density with LLLT versus sham.
Evidence grade
moderate
Effect direction
positive
Panel relevance
not-panel-replicable
Key findings
- The review included eight studies comprising 11 double-blind randomized controlled trials.
- LLLT significantly increased hair density versus sham treatment.
- Subgroup analysis found effects in both men and women and in comb and helmet-type devices.
Protocol details
| Wavelengths | 650 nm |
|---|---|
| Irradiance | Not reported mW/cm2 |
| Fluence | Not reported J/cm2 |
| Session time | Not reported minutes |
| Frequency | Varied; lower-frequency treatment subgroup performed better than high-frequency treatment subgroup |
| Duration | Short and long courses were both represented |
| Treatment area | Scalp |
| Device type | Low-level laser comb and helmet devices |
Caveats
- Trial heterogeneity limits protocol certainty.
- Scalp-contact or near-scalp laser devices are not equivalent to standing in front of a body panel.