What Is Red Light Therapy?: Benefits, Side Effects, and How To Use It

Author : Ari Whitten
Medical Reviewer: Evan Hirsch, M.D.

Red Light Therapy Healthy Benefits

The popularity and excitement around red light therapy is on the rise as research continues to prove its tremendous amount of health benefits. The non-invasive treatment has been linked to boosting fat loss, preventing aging, healing wounds, stimulating hair growth, diminishing scars, and many other health-related items.

Glamour Magazine even claims, “Red Light Therapy May Actually Be the Fountain of Youth 1.”

Are all of these lofty claims the stuff of science fiction or is it worth the hype?

The truth is, it has been the subject of thousands of studies going back to the 1990s when NASA used red lights to grow plants. Ongoing research continues to confirm the health benefits of red light therapy and uncover new uses for the treatments. We all have jars, bottles, and tubes of medicines for our health needs, but we might be overlooking the minimally invasive and relatively cheap health benefits we can achieve using only light 2.

The Basics of Red Light Therapy

Red light and near-infrared (NIR) light therapy involve using wavelengths of light in the 660 nm to 890 nm range, a portion of the light spectrum that is considered “bioactive.” It is administered with either low-level lasers or LED lights. You may have also heard this referred to by any number of names including:

  • photobiomodulation (PBM)
  • low-level light therapy (LLLT)
  • soft laser therapy
  • cold laser therapy
  • biostimulation
  • photonic stimulation
  • low-power laser therapy (LPLT)

RLT can also be used with photosensitizing medications in a process called “photodynamic therapy”. In this case, the light is only used as an activating agent for the medication.

The Science Behind Red Light Therapy

It is believed that red light causes a biochemical effect in cells that strengthen the mitochondria. A cell’s energy is created in the mitochondria as adenosine triphosphate (ATP). You can think of the mitochondria as the powerhouse of the cell. By increasing ATP production, the cell has more energy to function more efficiently and repair damage.

Red light therapy doesn’t cause damage to the skin’s surface, which differs from laser or intense pulsed light (IPL) therapy. Laser and IPL work by causing damage to the outer layer of skin, inducing tissue repair. Differently, red light therapy penetrates only about 5 millimeters into the skin, directly stimulating cell regeneration.

Red light therapy is also thought to contribute to hormesis, building up the cell’s anti-oxidant and anti-inflammatory defense systems. According to the National Institute of Health, “Hormesis is a term used by toxicologists to refer to a biphasic dose-response to an environmental agent characterized by a low dose stimulation or beneficial effect and a high dose inhibitory or toxic effect 3. In the fields of biology and medicine, hormesis is defined as an adaptive response of cells and organisms to a moderate (usually intermittent) stress.”

The Benefits of Red Light Therapy

There is no doubt humans need light in order to be healthy. When exposed to natural light, the skin absorbs Vitamin D, which is a critical nutrient that prevents bone loss and reduces the risk of various cancers, weight gain, and heart disease. Natural light also wards off seasonal depression, improves sleep, and reduces the health risks associated with fluorescent lights, but it does come with its potential risks such as skin damage and cancer.

The, noninvasive and safer option of bioactive spectrum red light and NIR light, provide an even greater range of health benefits including:

Wound Healing

Red light and near-infrared light therapy have been shown to be proficient in healing wounds. This is accomplished in several ways:

  • Cleaning up dead and damaged skin cells. (The process is known as “phagocytosis.”)
  • Stimulating collagen production and the health of the extracellular matrix.
  • Stimulating the capillaries and promotes new connective tissue on the wound’s surface.

For Skin

Red light’s ability to stimulate collagen synthesis and fibroblast formation makes it ideal for repairing damaged tissue from UV rays. A 2013 issue of Seminars in Cutaneous Medicine and Surgery featured a review of the research that highlighted dozens of studies proving photobiomodulation has anti-aging properties which can reduce the signs of aging, rosacea and other skin issues like fine lines and stretch marks.

Fibromyalgia, Chronic Fatigue, and Increased Energy

Research shows that it is highly effective at safely treating fibromyalgia and restoring energy to those with fatigue.  Studies show that red light and near-infrared light therapies offer:

  • Enhanced quality of life for fibromyalgia patients
  • Decreased pain
  • Decreased muscle spasm

Hashimoto’s Hypothyroidism

A 2013 randomized, placebo-controlled study of hypothyroid patients showed that people who received near-infrared light therapy saw dramatically improved thyroid function and greatly reduced thyroid antibody (TPOAb) levels.

In fact, 47% of patients were able to stop their medication completely. A follow-up treatment  nine months later found that the effects were still evident in the patients.


Research combining red light therapy with massage found that there was a 71% reduction in cellulite. Another study assessing it on skin health found that “91% of subjects reported improved skin tone, and 82% reported enhanced smoothness of skin in the treatment area4.”

Increased Bone Healing

It has been shown to speed the healing process for broken and fractured bones. In broken bones, ATP production is interrupted and cells begin to die from a lack of energy. Red and near-infrared light have been shown to:

  • Stimulate energy production in the bone cells
  • Increase bone growth factors
  • Modulate inflammation

Improved Eye Health

Studies show that red and near-infrared light therapy helps improve vision in patients with age-related macular degeneration (AMD). It also appears to improve edema, bleeding, metamorphosia, scotoma, and dyschromatopsia in some patients5.

Anxiety and Depression

A 2009 study took 10 patients with anxiety and depression, including PTSD and drug abuse, and gave them a four-week treatment with red light. By the end of the study, 6 out of 10 patients reported remission of their depression, and 7 out of 10 patients reported remission in their anxiety6.


Chronic inflammation is recognized as a major contributor to most chronic diseases, including heart disease, depression, cancer, and Alzheimer’s. Studies have shown that red and near-infrared light therapy is as effective for anti-inflammation as routinely prescribed non-steroidal anti-inflammatory drugs (NSAIDs).

Improved Cognitive Performance

Researchers have found that transcranial near-infrared light benefits the brain and cognitive performance. The same light therapy treatments have been found to improve sustained attention, short term memory in young adults, and improved memory in older adults with impaired memory7.


Because red light speeds wound healing, stimulates the production of collagen, and is highly anti-inflammatory, it has been shown to be an effective treatment for people suffering from tendinopathy and tendonitis8.

Increased Fertility

Research has shown great promise for using red light therapy for increased fertility. A study in Denmark found that it improved pregnancy rates by 68% where IVF had previously failed. Research also indicates that it increases sperm motility, leading to higher fertility rates in males 9.

Decreased Diabetes Symptoms

Studies show that red light therapy is effective in restoring diabetic patients’ normal healing ability by stimulating mitochondria and increasing the production of ADP. Additional studies show that light therapy helps to relieve pain, improve nerve function, and improve foot skin microcirculation in diabetic patients 10.

Oral Health

Red light therapy has proven effective for numerous aspects of oral health, including:

  • Combat viral and bacterial infections of the mouth (tonsillitis, herpes, cold sores)
  • Reduce mouth pain
  • Facilitate tooth growth/tooth movement and reduce pain for individuals with corrective braces
  • Help diabetics with gum problems and periodontal disease
  • Reduce thrush (yeast in the mouth/candidiasis)

Pain Relief

Red and near-infrared light therapy have proven effective in pain relief in a number of areas throughout the body. Red light therapy reduces pain for the following conditions:

  • Chronic neck pain
  • Back Pain
  • Knee pain
  • Fibromyalgia
  • Chronic joint disorders
  • Sacroiliac joint pain

Improved Immune System Function

Time and time again, red light therapy research has shown to improve immune systems in both animals and humans.

  • In animal studies, those inoculated with cancer and weakened immune systems saw increased lifespans.
  • Red light therapy boosted the immune system and T cells of preoperative cancer patients without increasing tumor size.
  • Red light therapy has shown to aid in wound healing by modulating immune function.
  • An animal model of multiple sclerosis showed that just two treatments done over a 14-day period led to significant improvement and with less brain cell damage11.

Respiratory Health

Research indicates that it is effective in improving the quality of life for those who suffer from chronic respiratory diseases, such as asthma, COPD, bronchiectasis, and ILD. Additional studies show that red light therapy is effective for patients with chronic obstructive bronchitis.

Traumatic Brain Injury and Spinal Cord Injury

Patients suffering from a traumatic brain injury (TBI) report improved cognition, better sleep, and enhanced muscle recovery from their injury after receiving red light therapy.

Scientists believe red light therapy increases ADP production in those who have suffered a stroke, thus speeding recovery.

Research indicates that near-infrared light therapy is a promising treatment for spinal cord injuries.

Improved Quality of Sleep

Studies in China indicate that red light therapy  naturally increases melatonin levels in patients suffering from insomnia, thus improving the quality and ability to fall asleep12.

Enhanced Muscle Gain, Strength, Endurance, and Recovery

Muscle tissue is more densely packed with mitochondria than nearly any other cell, tissue, or organ in the body. ATP is needed for every muscle twitch and movement. For this reason, it has numerous benefits for building muscle, preventing fatigue, and improving endurance.

Some of the significant finds involving red light therapy include:

  • Greater reduction in fatigue
  • Red light therapy prior to exercise significantly lowers levels of creatine kinase (a marker of fatigue)

Brain Health

Researchers found that red light therapy may significantly slow the progression of Alzheimer’s and Parkinson’s disease, including better cognitive performance and memory, improved cellular repair of neurons, and decreased brain inflammation.

Weight Loss

Studies show that red light therapy has an impact on reducing fat mass, fat tissue, and eliminating cellulite.

  • Studies have shown red light therapy helped shave 3.5 to 5.17 inches off waist and hip circumference in just four weeks.
  • In another study, participants lost 2.99 inches across all body parts in just 14 days.
  • Studies have shown that red light therapy dramatically increases exercise related fat lossRed Light Therapy Benefits

Possible Side Effects of Red Light Therapy

The National Center for Biotechnology Information has noted, “The non-invasive nature and almost complete absence of side-effects encourage further testing in dermatology.” While there is not enough information known about the effects of red light on the eyes, it is a good idea to use precaution and always wear protective eyewear.

How Do You Get Red Light Therapy?

If you are interested in receiving red light therapy treatments, you should first consult your dermatologist, oncologist, orthopedic, primary care doctor, rheumatologist or neurologist about treatment options. To find a local red light therapy option, many spas, medical facilities, and fitness studios offer various forms of red light therapy. From small wands to entire beds, there are also a number of FDA approved at-home devices now being sold in-store and online. You can check out the best at home red light therapy devices here.

Going Forward with Red Light Therapy

We are constantly receiving growing evidence from clinical research and studies supporting the health benefits of red and NIR light therapy. From improved cognitive performance to pain relief, red light therapy has rightfully earned its recent popularity.

For more information on Red Light Therapy, check out my “Ultimate Guide to Red Light Therapy.” or take a listen to my podcast “THE SCIENCE ON RED LIGHT THERAPY BENEFITS” WITH DR. MICHAEL HAMBLIN.”


Like this article?

Share on Facebook
Share on Twitter
Share on Linkdin
Share on Pinterest
Medically Reviewed ByEvan Hirsch, M.D.

Leave a comment

Scroll to Top