Science & Effects of Red Light Therapy
Since the beginning of the new millennium, increasing evidence shows that different wavelengths of light influence our body's biochemistry and therefore, its well-being-related functions. In particular, red (RED) and near-infrared (NIR) light is very effective. The red spectrum is visible to the eye and is absorbed mainly 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 several 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 have divided the effects of RED and NIR therapy into 9 categories, which provide a basic overview below. You may also click through to more specific information, including selected studies.
Recovery & Athletic Performance 
Hormonal System 
Skin, Hair & Nails 
Sleep & Circadian Rhythm 
Musculoskeletal System 
Mental & Cognitive Function 
Reduction of Inflammation 
Eyesight 
Longevity & Vitality Recovery & Athletic 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, increase strength and muscle mass. Red light therapy promotes energy production in the mitochondria, collagen production, increases testosterone (if applied to you-know-where) and thus has a positive effect on the physical aspects of our body.
Scientific studies
Red light therapy affects the mitochondria to increase the 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 can 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 improves hypertrophic response and muscle strength gains in healthy subjects. [ R]
Meta-analysis examined time to exhaustion, number of repetitions, isometric peak torque, and blood lactate levels. Positive results were found using a wavelength range from 655 to 950 nm. [ R]
Photobiomodulation using red and near-infrared light can increase the muscle mass gained after training, reduce inflammation and oxidative stress in the muscles. [ R]
Red and near-infrared light therapy can delay the development of muscle fatigue during exercise, decrease post-exercise blood lactate levels, and inhibit the release of inflammatory biomarkers. [ R]
Stimulation of the quadriceps with near-infrared light immediately after 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 hits, it subsequently strengthens them. Studies show a strong positive effect on the thyroid gland when using the light on the neck for 10 – 15 minutes per day (especially for females). In the same way red light therapy works in the case of crotch targeting in men (illuminating the parts where the light does not normally reach), women can also benefit from this. As a result, both testosterone production and spermatogenesis are increased. Positive effects are seen with the use of red and also near-infrared spectrum.
Scientific studies
Red light therapy is effective in increasing testosterone levels. [ R]Near-infrared light therapy promotes improved thyroid function. Patients have experienced a reduced need for the medicine used to treat an underactive thyroid gland (hypothyroidism) and reduced levels of the thyroid autoimmune disease marker (TPOAb). [ R]
Near-infrared light therapy positively affects thyroid hormone levels. [ R]
Treatment with infrared light raised concentration and number of mobile forms of the spermia, reduced their degenerative forms, elevated the level of serum sexual and gonadotropic hormones. [ R]
Irradiation of human spermatozoa with a near-infrared light improves their progressive motility. [ R]
Skin, Hair & Nails
As we age, our body gradually loses its ability to synthesize new collagen, resulting in the formation of wrinkles, and diminishing quality of hair and nails. Collagen is also important for wound and scar regeneration. While it’s beneficial to ingest specific amino acids or collagen from diet, to create maximum effect, collagen synthesis must be activated. This is where red and near-infrared light come 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 those locations, but they typically do not provide the optimal spectrum in the required irradiation strength.
Scientific studies
Red light therapy is an effective therapeutic method for the treatment of acne vulgaris. [ R]Red light therapy significantly improved hair counts 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 skin collagen density. [ R]
The use of red light has a positive effect on the amount of wrinkles and skin moisture on the cheeks of women. [ R]
Red light therapy has an anti-inflammatory effect and works on both acute and chronic inflammation. It is effective for 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 accelerating the healing process of burn wounds. [ R]
Sleep & Circadian Rhythm
Our body's processes are synchronized based on a 24-hour biorhythm called the circadian rhythm. In order to synchronise your rhythm, avoid artificial blue light before going to bed (e.g. with Blue Blockers glasses), and expose yourself to intense light soon after waking up. Photobiomodulation is ideal to use in the morning after waking up, as it produces a light spectrum that mimics the sunrise at an intensity of 30,000 lux (on a cloudy day you barely have a few hundred lux at home after sunrise). This creates a morning reset to your circadian rhythm, translating into energy and performance. Several studies have found improved sleep quality and increased melatonin levels when using red light therapy.
Scientific studies
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 their endurance performance. [ R]Infrared light was used in patients whose brain activity (EEG) was measured before, during and after light stimulation. The researchers concluded that infrared light may be useful 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 the intensity of pain. [ 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 its complex mechanism of action, red and especially near-infrared light therapy are very beneficial for our musculoskeletal system. They are great for prevention, and for 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.
Scientific studies
The application of near-infrared light is a safe and effective method of treating osteoarthritis of the knee. [ R]Reduction of knee osteoarthritis pain and improvement of 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 & Cognitive Function
Therapy through the red and the near-infrared spectrum 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 intense light). However, it is beneficial for anyone wanting to increase brain function through near-infrared therapy, the synthesis of activating neurotransmitters, or to reduce the negative effects of today's hectic, modern lifestyle.
Scientific studies
After 2 weeks of shining near-infrared light on the forehead, a significant improvement in the Hamilton Depression and Anxiety Scale was observed. 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 disease and possibly other neurodegenerative diseases such as multiple sclerosis and amyotrophic lateral sclerosis. [ R]
Near-infrared light reduced headache days, acute medication intake and the intensity of pain 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 traumatic brain injury patients even years after 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 medial prefrontal cortex dysfunction. [ R]
Reduction of Inflammation
Red and near-infrared light help reduce inflammation wherever it shines at sufficient intensity. Photobiomodulation using red and near infrared light can be used to locally target swelling, inflamed nodules, strained tendons, sore teeth, injured muscles, or even chronic inflammation in joints. It also helps to reduce chronic inflammation throughout the body.
Scientific studies
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 the effective reduction of inflammation, photobiomodulation can be used to treat problems such as osteoarthritis, joint injuries and excessive swelling without the side effects that are common with drugs that reduce inflammation 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 carpal tunnel syndrome patients. [ R]
Treatment of tennis elbow with LLLT shows significant improvement in functional parameters such as tenderness, strength and pain in the long term. [ R]
Near-infrared light combined with exercise is effective in relieving pain, improving grip strength, and in the 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 it can be assumed that it can shorten the time needed to achieve complete healing. [ R]
Eyesight
You may often hear about the negative effects of light on our eyes, whether by sitting too close to the TV or looking directly at the sun without glasses. Even though photobiomodulation uses intense light (visually, the red component; the 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 into the light with your eyes closed, despite the strong intensity. This strengthens them for any other light during the day. Quite literally, you can see for yourself that photobiomodulation works.
Scientific studies
Near-infrared light helps against complex ocular and neurological diseases such as early macular degeneration or age-related macular degeneration. [ R]Red light improves eyesight, especially in the elderly. It works by increasing cellular energy in the retina, which decreases with age. This results in better colour recognition and also better low-light visibility. [ R]
Longevity & Vitality
Perhaps the greatest promise of red and near-infrared light therapy lies in maintaining 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 will age. It is the positive action on mitochondria that is a big 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 right away, consistent application supports the longevity effect. When you look back over the many years of daily phototherapy application, you’ll smile at the fact you haven't aged a day.
Scientific studies
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 the mitochondria to increase the 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 exercise functional capacity and less frequent angina symptoms during exercise stress 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]
