Photobiomodulation (PBM), a form of nonthermal light therapy utilizing nonionizing light in the visible, near-infrared, or infrared spectra, has both direct effects (at the level of the mitochondria, the primary chromophore in humans) and indirect effects (via modulation of downstream signal transduction and cellular responses). As a result, it is thought to stimulate energy production, reduce oxidative stress, and decrease inflammation. PBM has been clinically studied in a large number of conditions and disease states, and has the advantage of being generally safe and cost-effective. The effects of PBM in autoimmunity, fibromyalgia, muscular function, neurological conditions, long COVID-19, carpal tunnel syndrome, radiation dermatitis, and oral mucositis are reviewed in this article, and additional opportunities for research are identified.
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