Umbrella review of low-level light therapy: evidence across clinical conditions

Published October 15, 2026. The review found encouraging patterns for selected uses, especially oncology-related oral mucositis, but most underlying reviews were methodologically weak and safety reporting was incomplete.

Song E, Ang L, Yim MH, Choi S, Kim J.
Lasers in Medical Science · Publication date: 2026-10-15
Added to site: 2026-10-16
DOI: 10.1007/s10103-026-05064-3

Version of record published October 15, 2026.

Modalities

Photobiomodulation

Clinical focus

Evidence synthesis, Safety reporting, Clinical applications

Population

Human evidence across multiple clinical conditions

Sample

100 systematic reviews, 1,164 eligible primary-study occurrences and 790 unique primary studies; the cumulative reported sample was not a count of unique participants

Intervention / method

Review-level mapping of non-thermal low-level light therapy, PBM and LED interventions across conditions, with AMSTAR 2 appraisal and study-overlap analysis.

Comparator

Included reviews used sham, placebo, standard-care and active comparators; no umbrella-level pooled efficacy estimate was calculated

Clinician summary

Of 100 reviews, 62 reached favorable conclusions, 34 were neutral or mixed and 4 were unclear. Sixty reviews were rated critically low and 30 low confidence with AMSTAR 2. Fifty-seven reviews did not report adverse-event information.

How to interpret the findings

Direction-of-conclusion counts are descriptive, not pooled efficacy or certainty estimates. Intervention parameters and outcomes varied widely, some primary studies recurred across reviews, publication bias was not assessed at umbrella level, and harms denominators were often missing.

Equipment and disclosures

No single device or manufacturer represents this multi-condition review. No BrainMaster attribution.

Supported by the Korea Institute of Oriental Medicine (KSN2512013). The authors declared no competing interests. The full publisher page was checked. No correction, retraction or concern relation appeared in the Crossref record; this is a bounded check. AI-assisted review.

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