de Freitas · IEEE journal of selected topics in quantum electronics : a publication of the IEEE Lasers and Electro-optics Society 2016 · narrative review · n=?

Proposed Mechanisms of Photobiomodulation or Low-Level Light Therapy.

Level 5 - mechanism / opinion, no new human data

Narrative review of proposed biological mechanisms with no original human clinical data

PubMed 28070154 · doi:10.1109/JSTQE.2016.2561201 · record verified 2026-08-26

What was done

Narrative review summarizing proposed molecular, cellular, and tissue mechanisms of photobiomodulation (PBM) or low-level light therapy (LLLT).

What was found

The abstract reports no quantitative data. It describes hypothesized mechanisms including absorption of near-infrared light by cytochrome c oxidase to dissociate inhibitory nitric oxide and increase ATP production, activation of light-sensitive ion channels allowing calcium influx, and downstream signaling via reactive oxygen species, cyclic AMP, nitric oxide, and calcium that activates transcription factors for protein synthesis, proliferation, anti-inflammatory signaling, and antioxidant defenses.

Why it matters

Provides a mechanistic framework outlining how light absorption at the cellular level may lead to therapeutic downstream effects.

Limits

Narrative review discussing biological mechanisms without primary human trial data, quantitative metrics, or study counts in the abstract.