Late last year, I found myself with way too much money left in my flexible spending account (FSA) and went on a bit of a shopping spree. I treated myself to a few pairs of new glasses and then stocked up on basics like pricey over-the-counter meds, sunscreen and a first-aid kit. With nearly $200 dollars left to spend, I started scrolling through FSA-approved products online and landed on a pair of FDA-cleared red-light therapy slippers. Happy to have found something that would use up the rest of my money, I added them to my cart thinking my mother, who has terribly arthritic feet, might like them. It wasn't until they showed up at my door that my health-editor instincts kicked in and I wondered, do these things actually work?
Many of these products and experiences are relatively cheap, easy to use and, according to manufacturers, able to ease joint pain, increase testosterone, spur weight loss, speed muscle recovery and so much more.
But when I started digging into the data, I quickly realized that the answer to my original question, "Does red-light therapy actually work?" was a bit more complicated.
What is red-light therapy?
Red-light therapy has been around for more than 50 years. It's said to have been discovered in 1967 by a researcher named Endre Mester at Semmelweis Medical University in Hungary. While attempting to replicate an experiment that used a ruby laser to cure tumors in rats, he discovered that his lower-powered laser didn't eradicate any tumors but did inspire faster hair growth and better wound healing in rats.
Since that time, red-light therapy has gone by more than 75 aliases, including low-level light/laser therapy, cold laser therapy, monochromatic infrared light energy therapy and photostimulation.
However, in more recent years, researchers have encouraged the use of the term photobiomodulation (PBM) therapy, which they feel is more representative of the practice. For this article, the terms red-light therapy and PBM are used interchangeably.
The North American Association for Photobiomodulation Therapy defines PBM as a form of nonthermal light therapy that utilizes nonionizing forms of light sources, including lasers, LEDs, and broad-band light, in the visible and infrared spectrum.
PBM, therefore, is different from other forms of light therapy, like infrared saunas -- which uses far-infrared radiation to heat the body -- and intense pulsed light, which uses high-intensity light sources to target the surface of the skin.
How does red-light therapy work?
PBM involves exposing an area of the body to visible and infrared light, much in the same way that daylight therapy is used to fight seasonal affective disorder. But what happens after that is still being disputed.
According to the prevailing theory, these wavelengths of light penetrate the skin where they are absorbed by cells and give the mitochondria -- the powerhouse of the cell -- a little boost. The mitochondria then produce more energy-revving adenosine triphosphate (ATP). And more ATP means higher functioning cells that can get to work doing all the great things cells do, like repairing and rejuvenating tissue.
What is red-light therapy used to treat?
PBM is widely used for pain reduction, wound healing, and inflammatory-related conditions like arthritis. But in recent years it's also been sold as a treatment for a wide variety of issues, including but not limited to:
- Low testosterone
- Poor sleep
- Traumatic brain injury
- Weight gain
Is red-light therapy safe?
PBM is by and large considered safe, but burns have been reported by consumers using Anodyne Therapy devices, which sit directly on the skin. And Neutrogena recently recalled its light therapy mask over concerns of eye injury.
Is red-light therapy effective?
When PBM manufacturers such as Joovv claim their products are backed up by thousands of studies, they're not lying. But what they're failing to tell you is that the majority of those studies are still preliminary.
Meta-analyses examining the available research almost always conclude that the evidence is insufficient, the mechanism of action is unclear, and treatment and dosage guidelines aren't well established (though the World Association for Photobiomodulation Therapy is working to change that).
Health insurance companies, like Aetna, agree. Even the Centers for Medicare & Medicaid Services has refused coverage, stating "the use of infrared devices is not reasonable and necessary for treatment of Medicare beneficiaries for diabetic and nondiabetic peripheral sensory neuropathy, wounds and ulcers, and similar related conditions, including symptoms such as pain arising from these conditions."
That said, a 2018 review focused on the efficacy of home-use PBM devices for nonaesthetic purposes found that these products have "good potential for effective and safe treatments in a variety of medical conditions requiring frequent sessions" but that higher-quality research is needed.
It should be noted, though, that the researchers were only able to identify 11 relevant studies, and that the largest study of the bunch, which still only included 60 patients, was the one study that failed to show favorable results.
PBM appears the most promising when applied to inflammatory-related conditions, like arthritis, and wound healing. A 2005 Cochrane review found that PBM can decrease pain and morning stiffness in people with rheumatoid arthritis but the effects are modest and quickly dissipate. (The results were more mixed for osteoarthritis.)
And two individual studies looking at wound healing -- one focused on using PBM to treat cold sores on the lips caused by Herpes labialis and the other focused on diabetic foot ulcers -- both found that PBM significantly reduced the time it took wounds to heal.
The bottom line
PBM is still considered experimental but it is likely safe. If you're curious, talk to your doctor about whether it's right for you or if there are other cheaper and more effective strategies you could try first.
The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.