Red Light Therapy: Potential Applications
Lilian White, MD
November 2, 2026
Red light therapy (also known as photobiomodulation) uses red and near-infrared lasers or light to affect cellular activity. This differs from bright light phototherapy used to treat seasonal affective disorder. Red light therapy was first used in the 1960s for wound healing. Currently, red light therapy is marketed for a wide variety of conditions including muscle fatigue, warts, mucositis, inflammatory arthritis, and near-sightedness.
Red light therapy is thought to reduce oxidative stress. When cells are under oxidative stress, nitric oxide is produced and inhibits adenosine triphosphate (ATP) synthase. This results in lower levels of ATP. Photons from red light cause nitric oxide to dissociate, allowing ATP to be produced. Red light therapy promotes collagen synthesis and angiogenesis to promote wound healing.
While claims of benefit are often overstated compared to the low certainty supporting evidence, red light therapy has many potential applications. One of the most well-studied indications for red light therapy is treating oral mucositis in patients with cancer. In randomized trials, patients experienced a 65% reduction in severe oral pain and a 54% reduction in severe oral mucositis.
Based on a single small study, red light therapy may provide relief for primary dysmenorrhea. Studies evaluating red light therapy for treatment of myopia in children are promising. Some dermatologic conditions, including acne, androgenic alopecia, wound healing, and mild photoaging, may also be treated with red light therapy. There are currently over 2,000 trials in the Cochrane database actively studying red light therapy for conditions, including temporomandibular joint dysfunction, tendinopathy, scars, plantar fasciitis, and postoperative pain.
While animal studies on red light therapy appear to be promising for treating and preventing neurodegeneration by reducing neuroinflammation, reducing beta-amyloid plaque burden and production, and modulating gene expression associated with Alzheimer disease, human trials are limited or in progress. Red light therapy does not appear to cause significant harm or benefit in patients with acute ischemic stroke. Red light therapy likely doesn’t reduce the duration of orthodontic treatment or impact nonexudative, age-related macular degeneration.
Overall, red light therapy appears to be safe. The most common adverse effect is erythema of the skin, which is self-limited and due to vasodilation related to heat exposure. DNA damage associated with ultraviolet and blue light does not occur in red light therapy. Patients with skin of color may experience hyperpigmentation and blistering with light emitting diode (LED) red light therapy. LED red light therapy also has the potential to cause retinal damage.
Recommended parameters for red light therapy may vary based on indication and are not well-studied. Red light therapy may be delivered by laser or LED. Common parameters include wavelength, power density, fluence, treatment time, distance from skin, and power density. Infrared or near-infrared lights have a wavelength of 620 to 1440 nm. Devices are typically placed directly on the skin or at a close distance of 1 to 20 cm away. As this therapy is an active area of investigation, it is too early to make strong recommendations regarding treatment parameters.