Light therapy treatments have been tested in hundreds of peer-reviewed clinical trials, and found to be safe and well-tolerated. [1,2] But can you overdo light therapy? Excessive light therapy use is unnecessary, but it’s unlikely to be harmful. The cells in the human body can only absorb so much light at one time. If you keep shining a light therapy device on the same area, you won’t see added benefits. This is why most consumer light therapy brands recommend waiting 4-8 hours between light therapy sessions.
Dr. Michael Hamblin of Harvard Medical School is a leading light therapy researcher who’s participated in over 300 phototherapy trials and studies. Though it won’t improve results, Dr. Hamblin believes that excessive light therapy use is generally safe and won’t cause skin damage. [3]
Conclusion: Consistent, Daily Light Therapy is Optimal
There are many different light therapy products and reasons to use light therapy. But in general, the key to seeing results is to use light therapy as consistently as possible. Ideally every day, or 2-3 times per day for specific problem spots like cold sores or other skin conditions.
Sources and References:
[1] Avci P, Gupta A, et al. Low-level laser (light) therapy (LLLT) in skin: stimulating, healing, restoring. Seminars in Cutaneous Medicine and Surgery. Mar 2013.
[2] Wunsch A and Matuschka K. A Controlled Trial to Determine the Efficacy of Red and Near-Infrared Light Treatment in Patient Satisfaction, Reduction of Fine Lines, Wrinkles, Skin Roughness, and Intradermal Collagen Density Increase. Photomedicine and Laser Surgery. Feb 2014
[3] Hamblin M. “Mechanisms and applications of the anti-inflammatory effects of photobiomodulation.” AIMS Biophys. 2017.