What precautions should be taken before using red light therapy?

Before starting red light therapy, several precautions should be taken to ensure safety and maximize efficacy. First and foremost, users must verify the quality and specifications of their device, ensuring it emits light in the therapeutic range (typically 630–670 nm for red and 810–850 nm for near-infrared) and is free from harmful UV emissions. Reading the manufacturer’s guidelines regarding distance, duration, and frequency is essential.

Medical precautions are critical for specific groups. Individuals taking photosensitizing medications must consult a healthcare provider. These medications include certain antibiotics (tetracyclines, fluoroquinolones), non-steroidal anti-inflammatory drugs (NSAIDs like ibuprofen in high doses), diuretics, retinoids (isotretinoin/Accutane), and some antidepressants. While RLT is not UV, the cumulative light load on sensitized systems is not fully mapped for every drug. Similarly, people with a history of skin cancer, active cancer, or pre-cancerous lesions should avoid treating those specific areas unless cleared by an oncologist, due to the theoretical risk of stimulating cell proliferation in malignant tissues.

Pregnant women are often advised to exercise caution, not because RLT is proven harmful (there is no evidence of teratogenicity), but because comprehensive clinical trials on pregnant populations are limited. As a precaution, abdominal treatment is usually discouraged during pregnancy. People with epilepsy sensitive to flashing lights should ensure their device uses continuous wave emission rather than pulsed modes that could trigger seizures, although most RLT devices use steady light. Finally, removing makeup, lotions, or barriers that could reflect light or heat up is recommended to ensure optimal penetration and prevent superficial heating. A patch test on a small area of skin for 2-3 days can help identify any unexpected sensitivity before committing to full sessions.