Is red light therapy safe?

Red light therapy has an excellent safety profile, with no serious adverse events reported in published clinical trials spanning thousands of participants. Unlike ultraviolet light, red and near-infrared wavelengths do not damage DNA or increase skin cancer risk. The most commonly reported side effects are mild and temporary: slight warmth during treatment, occasional temporary redness at the treatment site, and rare mild headaches. However, there are important precautions to follow. Always use protective eyewear rated for the specific wavelengths being used, as direct exposure to high-intensity light sources can potentially damage the retina over time. If you take photosensitizing medications — including certain antibiotics (tetracyclines, fluoroquinolones), retinoids, or some antidepressants — consult your doctor before starting treatment, as these drugs can increase light sensitivity. People with active skin cancers or lesions in the treatment area should avoid red light therapy on those areas until cleared by a dermatologist. Pregnant women should consult their OB-GYN, as limited research exists for this population. Reputable centers calibrate their devices regularly and train staff on proper protocols to ensure safe, consistent treatment delivery.

Reviewed by Chad Waldman, Analytical Chemist · Last updated May 2026

About Red Light Therapy

Red (630-660nm) and near-infrared (810-850nm) light is absorbed by cytochrome c oxidase in mitochondria, enhancing electron transport chain activity, increasing ATP production, and modulating reactive oxygen species signaling.