Evidence of red light therapy

Evidence suggests red and near-infrared light therapy can help in some settings, but benefits depend on the condition, wavelength, intensity, and device. Skin and hair benefits are supported by clinical use and studies; vision findings are promising but preliminary, and results are not uniform across applications.

1. Skin and hair — Teo Soleymani: Red-light therapy has evidence for increasing skin vascular flow and is used for hair restoration, post-procedure recovery, and skin health after UV damage. A mouse study found less UV-related skin change when animals received red light beforehand. Soleymani also cautions that standalone effectiveness is uncertain and devices vary substantially. 1

2. Vision — Jeffery Lab: Human studies using red light reported improved visual function in adults over 40; the discussion also describes reduced retinal reactive oxygen species and reduced accumulation of drusen, or cholesterol deposits. The findings are exciting but recent, so more evidence is needed. 2 3

3. Mitochondria and other uses: Red and near-infrared light can reach cellular mitochondria and may improve mitochondrial function by increasing ATP and reducing reactive oxygen species. Reported applications include acne, wound healing, scars, and skin appearance; some trials show benefits while others find no significant effect, and effects are often mild to moderate. 4 5

4. Devices and protocols: Results vary with wavelength, energy, light density, and treatment duration; some marketed devices may not deliver enough energy. Peer-reviewed research and clearly specified device parameters matter when judging a product. 6