Red light therapy works through a process called photobiomodulation. Certain wavelengths of light are absorbed by components inside the cell, which may influence how the cell produces and uses energy.
Researchers have proposed several mechanisms that may explain the effects reported in light therapy studies.
Supporting Cellular Energy Production
One of the most discussed theories behind photobiomodulation involves mitochondria.
Mitochondria are responsible for producing much of the energy required by cells. This energy, in the form of adenosine triphosphate (ATP), powers nearly every cellular process, including tissue maintenance and repair.
Research suggests that red and near-infrared light may be absorbed by an enzyme in the mitochondrial respiratory chain called cytochrome c oxidase. This interaction has been studied for its potential influence on cellular energy metabolism.
If cells receive usable energy more efficiently, the theory goes, tissues under stress—such as tired muscles, recovering skin, or irritated joints—may be better supported during routine maintenance and repair.
Modulating Inflammation and Oxidative Stress
Photobiomodulation has been widely studied for its potential effects on inflammatory signaling and oxidative stress.
The goal is not to eliminate inflammation completely, since inflammation plays an important role in recovery and immune function. Instead, researchers are interested in whether light exposure can help maintain an appropriate inflammatory response.
This is one reason red light therapy continues to attract interest in sports recovery and musculoskeletal research.
Supporting Circulation
Blood vessel function and local circulation help deliver oxygen and nutrients to working and recovering tissues.
Photobiomodulation has been investigated for its potential effects on vascular signaling and blood flow. Improved circulation is one proposed explanation for why some users report feelings of relaxation and reduced muscle tightness after a session.
Stimulating Fibroblast and Collagen Activity
Fibroblasts are specialized cells responsible for producing collagen, the structural protein that gives skin its firmness and elasticity.
Laboratory and clinical studies have examined whether specific red wavelengths can influence fibroblast activity and collagen synthesis. This line of research underpins most of the skin-related claims associated with red light therapy.
However, biological plausibility is only the beginning. A mechanism that looks promising in a laboratory does not automatically mean that every commercial device will produce the same result for every user.
