What is the science behind red light therapy?
Last Updated: 21.06.2025 00:07
The healing starts when the absorbed wavelength reaches critical mass. Healing continues as photons come in. When the bag is full, healing stops. If the light continues to shine on the same spot, healing reverses as if the therapy had not been done. So it's essential for consumers to use quality vendors who actually test their lights with proper equipment. I hope this clears up some misunderstandings about red light therapy. I'm a bit obsessed with the subject, so please feel free to ask me questions. Thanks fo reading. PEACE
The infrared wavelengths have the deepest penetration into the brain. The frequency pulse entrains the brain waves to 10 hz or 40 Hz, corresonding to alpha (rest) and gamma (alert). The most popular use of red light therapy is anti-aging devices such as light domes and face masks. These usually offer red and infrared light, and can also be found with blue and yellow light. Blue combined with red is the best combination for acne symptoms.
Yep. We're like plants.
Infrared has a deeper reach into the body than red. Infrared is good for pain, arthritis, inflammation, healing poorly healed fractures, and brain modulation. Blue is especially helpful in reducing the symptoms of acne. Presumably because it's close to the UV wavelengths, it has the ability to kill the P. acnes bacteria in a completely non-invasive manner and with no side effects. That is granted that the person wears goggles, as blue light can hurt the eyes and definitely blocks the production of melatonin.
Successful treatment requires that the wavelength and energy quantity (fluence) fit within a therapeutic window. Marketing and non-medical people being in charge of writing product descriptions allows the market to get very confusing for the buyer. Vendors fight to outdo one another to the point that now every light on Amazon supposedly has 100 mW/cm2 irradiance when holding the device on the skin. Some claim 200 mW. The consumer has no way to know if these values are accurate.
This is a huge challenge that the industry has to fix, because the wrong dose of the right wavelength doesn't produce healthy change. When the mitochondria absorb the right amount of photons, the body kicks off an ATP production cycle using the photon energy absorbed.
810 nm and 1070 nm are approximately the "strongest" wavelengths in that they have the deepest reach into the body. Most sucessful brain studies are performed with 810 nm and 1070 nm. The most exciting work in red light therapy is using 810 nm or 1070 nm along with a 10 Hz or 40 Hz pulse. Subjects with dementia, traumatic brain injury and Parkinson's show significant gains when treated within these parameters.
Light received changes drastically with distance and time. If the customer uses the wrong distance or the wrong treatment time per session, he or she will fail to see gains.
When you do light therapy with a low powered laser or LEDs, it's called cold laser, low level light therapy, or low level laser therapy. The keyword used in science is photobiomodulation, i.e. using light to change the biology. Red light therapy usually includes infrared light, and most consumer devices are a combination of red and infrared. Red is good for skin, pain, arthritis, and hair growth.
The reason LEDs work as well as lasers is that by the time the photons reach the body, there's no biological difference between an LED photon and a laser photon. The columnar aspect of the laser light falls out of the equation when the laser light hits the skin, because the skin is much more reflective than had been assumed.
The blue kills the bacteria and the red (ironically) reduces redness. Each on its own can reduce bumps and lesions. Red and infrared can reduce scars. Yellow also has a red-reducing effect. Red and infrared combined are the best lights for producing collagen and elastin, thereby reducing wrinkles. The biggest challenge for the red light buyer is dosing.
I spend a fair bit of time studying the science of light therapy, I feel the need to speak up. There are ove 7,000 studies on light therapy, the majority of them on red light, with infrared being a second close. Light therapy is done with both lasers and LEDs. The concept of LEDs being too weak was debunked years ago. That led to an explosion in the consumer light therapy market.
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