Scientific studies and publications on red light therapy
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Since the beginning of the new millennium, there has been increasing evidence that different wavelengths of light influence our body’s biochemistry and thus its well-being-related functions. In particular, red light (RED) and near-infrared light (NIR) are very effective. The red spectrum is visible to the eye and is mainly absorbed by the skin. Near-infrared light is not visible to the human eye. This light penetrates deeper into our body (unlike other wavelengths, which are absorbed by the skin), where it has a positive effect on our mitochondria, cells, organs and endocrine glands.
The new science of photobiomodulation has brought us thousands of studies (including human studies) over the past two decades showing that the therapeutic use of red and near-infrared light can support our bodies on virtually every level.
We’ve divided the effects of RED and NIR therapy into 9 categories, which provide a basic overview below. You can also click through for more specific information, including selected studies.
Athletic recovery and performance
Some of the most popular benefits of red light therapy are its use before training to improve athletic performance, or after physical activity to reduce inflammation in the body, speed up recovery, and increase strength and muscle mass. Red light therapy promotes energy production in mitochondria, collagen production, increases testosterone (if applied to you-know-where), and therefore has a positive effect on the physical aspects of our body.
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Scientific Studies - Athletic Recovery and Performance
Red light therapy affects mitochondria to increase production of the main energy source called ATP. [ R ]Red light therapy can improve muscle performance, reduce muscle fatigue during exercise, and improve muscle recovery.
Athletes, people with muscle injuries, and patients with Duchenne muscular dystrophy may benefit. [ R ]
Red light therapy improves muscle strength, reduces delayed onset muscle soreness (DOMS), and decreases the concentration of biomarkers of muscle damage more than cryotherapy. Based on these findings, the researchers concluded that photobiomodulation can improve muscle recovery after high-intensity exercise and is more effective than cryotherapy. [ R ]
Near-infrared light applied prior to eccentric training enhances the hypertrophic response and muscle strength gains in healthy individuals. [ R ]
The meta-analysis examined time to exhaustion, number of repetitions, peak isometric torque, and blood lactate levels. Positive results were found using a wavelength range of 655 to 950 nm. [ R ]
Photobiomodulation using red and near-infrared light can increase muscle mass gained after training, reduce inflammation and oxidative stress in muscles. [ R ]
Red and near-infrared light therapy has been shown to increase muscle endurance and improve recovery. It can increase the number of muscle contractions (exercise repetitions) by nearly 13% and extend the time until muscle fatigue sets in by more than 11%. Additionally, the therapy significantly reduces post-exercise levels of important biochemical markers, such as blood lactate, creatine kinase, and C-reactive protein, which are associated with muscle fatigue and inflammation. This makes it a powerful tool for improving performance and speeding recovery. [ R ]
Stimulation of the quadriceps with near-infrared light immediately following leg press and leg extension exercises resulted in reduced muscle damage, muscle soreness, and increased muscle mass, recovery, and athletic performance. [ R ]
Near-infrared light therapy performed immediately after leg press exercise resulted in greater strength gains compared to strength training without NIR therapy. The increase in thigh circumference was also slightly greater in the NIR group. [ R ]
Red light therapy in elite female basketball players had a positive effect on their endurance performance. [ R ]
Near-infrared light therapy enhances the effects of exercise in obese women undergoing weight loss. Improvement in lipid profile and reduction in adipose tissue suggest increased metabolic activity and altered fat metabolism. [ R ]
Hormonal System
Near-infrared light penetrates deep into the body and, depending on which endocrine glands it targets, it subsequently strengthens them. Studies show a strong positive effect on the thyroid gland when using the light on the neck for 10 to 15 minutes a day (especially for women). In the same way that red light therapy works in the case of targeting the groin in men (illuminating the parts where the light normally does not reach), women can also benefit from it. As a result, both testosterone production and spermatogenesis are increased. Positive effects are seen with the use of both the red and near-infrared spectrum.
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Scientific studies - Hormonal System
Red light therapy is effective in increasing testosterone levels. [ R ]Near-infrared light therapy promotes improved thyroid function. Patients experienced a reduced need for the medication used to treat an underactive thyroid gland (hypothyroidism) and reduced levels of the autoimmune thyroid disease marker (TPOAb). [ R ]
Near-infrared light therapy positively affects thyroid hormone levels. [ R ]
Infrared light treatment increased the concentration and number of motile sperm forms, reduced their degenerative forms, and elevated the level of serum sex and gonadotropic hormones. [ R ]
Irradiation of human sperm with near-infrared light improves their progressive motility. [ R ]
Skin, Hair and Nails
As we age, our bodies gradually lose their ability to synthesize new collagen, resulting in the formation of wrinkles and a decrease in the quality of our hair and nails. Collagen is also important for the regeneration of wounds and scars. While it is beneficial to consume specific amino acids or collagen from your diet, to create the maximum effect, collagen synthesis must be activated. This is where red and near-infrared light comes in. Increasing collagen production is the main reason why phototherapy has been used in beauty salons and dermatology. You can also find various infrared lamps and emitters in these settings, but they usually do not provide the optimal spectrum at the required radiation strength.
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Scientific Studies - Skin, Hair and Nails
Red light therapy is an effective therapeutic method for treating acne vulgaris. [ R ]Red light therapy significantly improved hair count in men with androgenetic alopecia. [ R ]
Red and near-infrared light therapy is a safe and effective method for skin rejuvenation, reducing wrinkles, fine lines and increasing the skin's collagen density. [ R ]
The use of red light has a positive effect on the amount of wrinkles and skin moisture on women's cheeks. [ R ]
Red light therapy has an anti-inflammatory effect and works on both acute and chronic inflammation. It is effective in accelerating wound healing and increasing collagen synthesis. [ R ]
Photobiomodulation is an effective and safe therapeutic method against burn scars in children. [ R ]
Low-level laser therapy is effective in speeding up the healing process of burn wounds. [ R ]
Sleep and Circadian Rhythm
Our body’s processes are synchronized based on a 24-hour biorhythm called the circadian rhythm. To synchronize your rhythm, avoid artificial blue light before bed (e.g., with blue-blocking glasses) and expose yourself to bright light right after waking up. Photobiomodulation is ideal for use in the morning after waking up, as it produces a spectrum of light that mimics sunrise at an intensity of 30,000 lux (on a cloudy day, you barely have a few hundred lux in your home after sunrise). This creates a morning reset for your circadian rhythm, which translates into increased energy and performance. Several studies have found improved sleep quality and increased melatonin levels when using red light therapy.
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Scientific studies - Sleep and Circadian Rhythm
Red light therapy led to improved sleep quality and also significantly increased melatonin secretion in elite female basketball players. It also had a positive effect on endurance performance. [ R ]Infrared light was used on patients whose brain activity (EEG) was measured before, during, and after light stimulation. The researchers concluded that infrared light may be helpful for patients with sleep problems. [ R ]
Near-infrared light reduced sleep disturbances in patients with chronic migraines. It also reduced headache days, acute medication intake, and pain intensity. [ R ]
People with traumatic brain injury (TBI) had an average increase in sleep duration of 1 hour per night after red and near-infrared light therapy. [ R ]
People with traumatic brain injury (TBI) have reported improved sleep after red and near-infrared light therapy. [ R ]
Musculoskeletal system
Due to their complex mechanism of action, red light therapy and especially near-infrared light therapy are very beneficial for our musculoskeletal system. They are great for prevention and for the regeneration of joints, tendons and even bones. This therapy can reduce inflammation while increasing collagen synthesis; two of the most important factors for a strong musculoskeletal system.
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Scientific studies - Musculoskeletal system
The application of near-infrared light is a safe and effective method of treating osteoarthritis of the knee. [ R ]Reducing knee osteoarthritis pain and improving microcirculation (circulation of body fluids - blood, tissue fluid, lymph - at the level of individual tissues) using near-infrared light. [ R ]
Near-infrared light therapy combined with exercise was more effective than exercise alone in treating patients with knee osteoarthritis. [ R ]
Both red and infrared light helped repair damaged bones. The infrared spectrum had better effects. [ R ]
Bones irradiated with near-infrared light show increased repair (osteoblastic proliferation), collagen deposition, and bone formation. [ R ]
Mental and Cognitive Function
Red and near-infrared spectrum therapy has a positive effect on our brain, psyche and mood. It is very effective for both depressive episodes and seasonal depression (when we often lack bright light). However, it is beneficial for anyone who wants to increase brain function through near-infrared therapy, the synthesis of activating neurotransmitters or to reduce the negative effects of today's modern and hectic lifestyle.
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Scientific Studies - Mental and Cognitive Function
After 2 weeks of near-infrared light on the forehead, significant improvement was observed on the Hamilton Anxiety and Depression Scale. No side effects were observed. [ R ]Near-infrared light therapy is proving to be an effective neuroprotective treatment for patients with Alzheimer's and Parkinson's and possibly other neurodegenerative diseases such as multiple sclerosis and amyotrophic lateral sclerosis. [ R ]
Near-infrared light reduced headache days, acute medication intake, and pain intensity in patients with chronic migraines. It also reduced sleep disturbances. [ R ]
Red and near-infrared light therapy for people with traumatic brain injury (TBI) not only improved their cognitive function, but patients experienced fewer episodes of post-traumatic stress disorder (PTSD). [ R ]
Red and near-infrared light applied to the skull leads to improved cognitive function in patients with traumatic brain injury, even years after the injury.
It also leads to reduced symptom severity in patients with post-traumatic stress disorder who share some of the same brain abnormalities with chronic TBI cases, including dysfunction of the medial prefrontal cortex. [ R ]
Reduction of inflammation
Red and near-infrared light helps reduce inflammation wherever it shines with sufficient intensity. Photobiomodulation using red and near-infrared light can be used to locally target swelling, inflamed nodules, pulled tendons, painful teeth, injured muscles, or even chronic inflammation in joints. It also helps reduce chronic inflammation throughout the body.
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Scientific Studies - Reducing Inflammation
Red and near-infrared light therapy can significantly reduce the level of inflammation in the body. [ R ]Photobiomodulation using red and near-infrared light can reduce inflammation in the brain, lungs, fatty abdomen, and various types of wounds. [ R ]
Due to its effective reduction of inflammation, photobiomodulation can be used to treat problems such as osteoarthritis, joint injuries and excessive swelling without the side effects common with inflammation-reducing medications such as NSAIDs (non-steroidal anti-inflammatory drugs - ibuprofen, aspirin, naproxen...). [ R ]
Near-infrared light relieves pain and symptoms, improves functional abilities, finger and hand strength in patients with mild or moderate carpal tunnel syndrome. [ R ]
Near-infrared light is effective against tingling, numbness, and improves grip strength in the hands of patients with carpal tunnel syndrome. [ R ]
Treatment of tennis elbow with LLLT shows significant improvement in functional parameters such as sensitivity, strength and pain in the long term. [ R ]
Near-infrared light combined with exercise is effective in relieving pain, improving grip strength, and subjective assessment of physical function in patients with lateral epicondylitis. [ R ]
Immediate pain relief and improved wound healing in oral mucositis (inflammation in the oral cavity associated with ulcer formation) after treatment with near-infrared light. [ R ]
Red light accelerates the healing process of chronic diabetic foot ulcers and can be assumed to shorten the time required to achieve complete healing. [ R ]
Vision
You may often hear about the negative effects of light on our eyes, whether it’s from sitting too close to the TV or looking directly at the sun without glasses. However, photobiomodulation uses intense light (visually, the red component; near-infrared is not visible to the naked eye). This may seem counterintuitive, but these wavelengths strengthen the eyes and vision, negating the effects of looking at screens and the negative effect of excessive blue light in general. This means that you can look at the light with your eyes closed, despite the strong intensity. This strengthens them for any other light during the day. You can literally see for yourself that photobiomodulation works.
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Scientific studies - Vision
Near-infrared light helps against complex eye and neurological diseases, such as early macular degeneration or age-related macular degeneration. [ R ]Red light improves vision, especially in older adults. It works by increasing cellular energy in the retina, which decreases with age. This results in better color recognition and also improved visibility in low light. [ R ]
Longevity and Vitality
Perhaps the greatest promise of red and near-infrared light therapy lies in maintaining the overall long-term vitality and longevity of our bodies. This type of light purposefully strengthens the cell’s energy factories—the mitochondria—directly affecting the lifespan of a given cell and how quickly we age. It is the positive action on mitochondria that is a major theme of the current anti-aging movement. Photobiomodulation using RED and NIR radiation is one of the most effective ways to achieve this. While you will feel some effects immediately, consistent application supports the longevity effect. When you look back on many years of daily light therapy, you will smile at the fact that you have not aged a day.
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Scientific Studies - Longevity and Vitality
Photobiomodulation using red and near-infrared light alters the course of aging in the central nervous system by improving neuronal survival and function and reducing gliosis and inflammation. [ R ]Photostimulation with red light and near-infrared light affects mitochondria to increase production of the main energy source called ATP. [ R ]
Red and near-infrared light therapy has a positive effect on the composition of the gut microbiome. [ R ]
Improved functional exercise capacity and less frequent angina symptoms during exercise testing in patients with advanced coronary artery disease after red light therapy. [ R ]
Near-infrared light therapy has demonstrated safety and efficacy in the treatment of ischemic stroke in humans when initiated within 24 hours of stroke onset. [ R ]
