Red light therapy (RLT), also known as photobiomodulation or low-level laser therapy (LLLT), is a treatment that exposes the skin to low levels of red light. It is proposed to assist in healing the skin, muscle tissue, and other parts of the body. It is thought to work by increasing the production of mitochondria, the energy sources of cells. This may improve cell function and repair.
What is Red Light Therapy?
Red light therapy is a noninvasive treatment that uses very low levels of heat and doesn’t hurt or burn the skin. Unlike the light used in tanning booths, it doesn’t expose your skin to damaging UV rays. It does this by using an LED (light-emitting diode) that emits the correct spectrum of light. In red light therapy, you expose your skin to a lamp, device, or laser with a red light. Red LED light travels deeper into the skin than blue LED light, which is sometimes used to treat skin surface conditions such as acne. When the light enters your skin, your mitochondria soak it up and make more energy, which helps cells repair themselves.
Red Light Therapy Devices
There are many different types of red light therapy devices, some of which can be used at home. But home devices are usually less powerful than those used in clinics and may be less effective or take longer to work. Red light therapy devices include:
- Red light therapy mask: This fits over your entire face and has red LED lights on the inside, pointed toward your skin. It is designed to be worn for a short length of time several times a week. It's used as a treatment for acne, wrinkles, or other facial skin concerns.
- Red light therapy bed: This looks like a tanning bed but has red LED lights instead of UV lights. It is big enough for you to lie down inside, and your whole body is exposed to red light.
- Red light therapy panel: This is a panel of red LED lights that you can mount on a wall or place on a table, either at a clinic or home. Panels range in size from small to large. Small panels are used for targeted areas such as your face, and large panels can target larger areas of your body.
- Red light therapy wand: These are handheld devices that have red LED lights at one end. You use them by moving the wand over your skin in the areas that you want to treat. They are used to treat very small areas, such as the back of the hands, one knee, or a particular spot on the face.
Research-Backed Benefits of Red Light Therapy
Research on the benefits of red light therapy is ongoing. While more research needs to be done, there is some evidence that it may be useful for several health and beauty concerns.
Red Light Therapy for Dementia
A 2021 research review found that in all 10 studies included in the review, red light therapy had benefits for people with dementia. In one of the studies, five people with dementia who had regular light therapy on their heads and through their noses for 12 weeks had better memories, slept better, and were angry less often. The review noted that many of these studies were small and lacked controls and that larger trials need to be done before any benefits can be confirmed.
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Red Light Therapy for Pain
Research shows that red light therapy may be useful for relieving some types of pain, particularly pain due to inflammation (irritation and swelling of body tissues). A review of 11 studies looking at the effect of red light therapy on pain found mostly positive results, though the authors said that more studies are needed. In another small study, people with temporomandibular dysfunction (TMD) had less pain, clicking, and jaw tenderness after red light therapy.
Red Light Therapy for Arthritis
A review of studies found that red light therapy may be a helpful short-term treatment for pain and morning stiffness for patients with rheumatoid arthritis. However, it doesn’t seem to be very helpful for other forms of arthritis, such as osteoarthritis.
Red Light Therapy for Tendinopathy
Tendinopathy is a condition that causes pain and loss of function in your tendons. A review of 17 clinical trials studying the impact of red light on treating tendinopathy found low-to-moderate quality evidence indicating that red light can help relieve pain or improve function.
Red Light Therapy for Hair Loss
A review of multiple studies found that red light therapy can be an effective treatment for androgenic alopecia, a genetic disorder that causes hair loss. Another review of 11 studies found similar promising results. In some studies, hair thickness improved as well as hair growth.
Red Light Therapy for Skin
Research shows red light therapy may smooth your skin and help with wrinkles. Researchers think it does this by stimulating collagen production, which helps improve skin elasticity. Research shows it also helps improve signs of sun damage.
Read also: At-Home Red Light Therapy Devices
Red Light Therapy for Acne
Research has found that red light therapy can be effective for acne treatment. This may have to do with its ability to help reduce inflammation. In addition to helping with active acne lesions, red light lasers may also help treat old acne scars.
Red Light Therapy and Weight Loss: Examining the Claims
Some providers use red light therapy as a weight loss treatment. This is often called body contouring, or body sculpting. Red light therapy may help reduce the circumference of your body in the area that was treated, but the effect will likely be temporary and not due to any real weight loss.
Does Red Light Therapy Work for Weight Loss?
Due to inconclusive research, there is some controversy surrounding the question of whether red light therapy can help with weight loss.
Studies include a pilot study from 2020 involving 60 adults with overweight. The results showed a modest 0.8-inch (2 cm) reduction in waist circumference following twice-weekly LLLT treatments over 6 weeks. However, there was no control group to compare the results with.
Another study, from 2017, specifically targeted abdominal girth using a combination of three wavelengths of low-level laser, including red, infrared, and blue. The study involved 18 females who each underwent a total of 12 LLLT sessions during the course of the study. The results showed significant reductions in upper, middle, and lower abdomen size, with all of the study participants experiencing positive results.
Read also: Weight Loss with Red Light Therapy: What the Science Says
In 2018, researchers looked into the potential benefits of LLLT with exercise training to reduce body fat. The study involved 49 females with obesity aged 20-40 years, divided into intervention and sham groups. The participants underwent three sessions per week of exercise training with phototherapy after exercise for 4 months. All participants experienced improvements. However, only those who received LLLT showed reduced interleukin-6, which is a marker of immune health, and increased WNT5 signaling, which is needed for the development of healthy cells. This group also experienced bigger changes than the sham group in relation to:
- Fat mass
- Insulin
- HOMA-IR, which is a measure of insulin resistance
- FGF21, which regulates carbohydrate and fat metabolism
Another study from 2017 also found that receiving LLLT in addition to treadmill walking resulted in a greater reduction in abdominal fat and body weight. However, one study actually found an increase in fat tissue thickness in 8 out of 17 participants.
Researchers still need to work out the definitive mechanism of action behind LLLT. However, it might relate to the absorption of laser light into the adipocytes, which leads to increased cyclic adenosine monophosphate production, a type of cell signal or messenger. This then stimulates an enzyme called cytoplasmic lipase, which converts triglycerides to fatty acids and glycerol. These substances can pass through pores, causing the adipocytes to shrink.
Additionally, one animal study from 2018 found that infrared photobiomodulation therapy, which is another name for LLLT, improved glucose metabolism and insulin regulation in the fat tissue of mice with obesity caused by a high fat diet. Photobiomodulation has also been shown to increase muscle mass gained after training.
Long-Term Weight Management Strategies
As the CDC explains, healthy weight management is about lifestyle rather than a specific diet or program. It is about establishing healthy eating patterns in combination with regular physical activity and stress management.
A review in Nutrients from 2020 reported that healthier alternatives to the Western diet tend to feature more plant-based foods, such as:
- Fresh fruits and vegetables
- Whole grains
- Legumes
- Seeds and nuts
These diets include the Mediterranean diet, the Dietary Approaches to Stop Hypertension (DASH) diet, and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet. They also tend to be lower in animal-based foods, especially fatty and processed meats.
Additionally, the American Association of Clinical Endocrinologists and the American College of Endocrinology recommend moderate-intensity aerobic exercise for at least 150 minutes per week for the medical care of people with obesity. They note better outcomes with increasing intensity and amounts of exercise.
There is also evidence that actively managing stress can help a person manage their weight. For instance, in one study from 2018, 45 adult participants received standard instructions for a healthy lifestyle. Of these, 22 people in the intervention group also attended an 8-week stress management program. This involved breathing from the diaphragm, doing progressive muscle relaxation, doing guided visualization, and receiving instructions about healthy dietary habits. The intervention group achieved a significantly greater reduction in BMI compared with the control group, with losses of 3.1 kilograms per square meter (kg/m2) in the intervention group compared with 1.74 kg/m2 in the control group.
Red Light Therapy Risks and Safety
Red light therapy appears to be mostly safe when used correctly, especially in the short term. Many forms of red light therapy are more effective when done at a doctor’s office rather than at home. That's because doctors can use stronger lights. Even at a doctor’s office, however, there are some risks. One early-stage clinical trial found that at high levels, red LED lights such as those used in red light therapy can cause blistering and redness on the skin. Red light therapy may also cause eye damage in some cases, so it is best to wear protective goggles when using a red light therapy device.
Contraindications
People who take medications that increase their skin or eye sensitivity should not use red light therapy. People who have a history of skin cancer or eye disease should speak with their doctor before using red light therapy. Pregnant or breastfeeding women should avoid red light therapy due to the lack of extensive research on its safety in these populations. Individuals with active skin conditions such as lupus, dermatitis, rosacea, or photosensitivity disorders should exercise caution, as the therapy may exacerbate these conditions. Those with a history of skin cancer or current skin lesions should consult a healthcare professional before proceeding with red light therapy.
Can it cause cancer?
There is no evidence that red light therapy causes cancer. Red light therapy does not use ultraviolet rays, a form of radiation found in tanning booths and sunlight that can lead to skin cancer.
Red light therapy during pregnancy
There is not a lot of research on the effects of red light therapy on pregnant people, but limited research suggests that it is safe. One study examined 380 pregnant women who had used laser light treatments during pregnancy and found that it was safe for both the parent and fetus.
Red Light Therapy Cost
The cost of this therapy can vary greatly depending on whether you are using a device at home or you are getting treatment in a clinic. But in general, red light therapy isn’t cheap - treatments can cost $80 a session or more. Red light therapy sessions in Roseville, CA, typically range from $100 to $500 per session. The cost varies based on the provider, session length, and treatment area.
If you decide to use a red light therapy device at home, note that it may not be as powerful or effective as devices used by doctors or other professionals. When choosing an at-home device to purchase, you can check whether it has been cleared by the US FDA, which means that it is safe and equivalent to other devices already on the market. When using a red light therapy device at home, make sure to use proper eye protection and follow all directions on the device.
How Many Red Light Therapy Treatments Do You Need?
The number of red light therapy treatments you need depends on what you are getting treatment for. But you will likely need ongoing sessions for weeks or even months.
Can You Overdo Red Light Therapy?
Yes, it’s possible to overdo red light therapy. “Because it’s light exposure on your skin, it can cause irritation and even burning,” Overall, doctors don’t recommend using red light therapy to try to lose larger amounts of weight, and to keep it off.
The Science Behind Red Light Therapy
LLLT is a noninvasive, nonthermal approach to disorders requiring reduction of pain and inflammation and stimulation of healing and tissue regeneration. Within the last decade, LLLT started being investigated as an adjuvant to liposuction, for noninvasive body contouring, reduction of cellulite, and improvement of blood lipid profile. LLLT may also aid autologous fat transfer procedures by enhancing the viability of adipocytes. However the underlying mechanism of actions for such effects still seems to be unclear. The studies as of today suggest that LLLT has a potential to be used in fat and cellulite reduction as well as in improvement of blood lipid profile without any significant side effects. One of the main proposed mechanism of actions is based upon production of transient pores in adipocytes, allowing lipids to leak out. Although the present studies have demonstrated safety and efficacy of LLLT in fat layer reduction, studies demonstrating the efficacy of LLLT as a stand-alone procedure are still inadequate.
Mechanism of Action
The mechanism is based on absorption of red and near-infrared photons by chromophores in the mitochondria (particular cytochrome c oxidase) leading to increases of mitochondrial membrane potential, oxygen consumption, adenosine triphosphate (ATP), a transient increase in reactive oxygen species (ROS) , and a release of nitric oxide (NO). Transcription factors such as nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) are activated leading to signaling pathways that promote cell survival, cell proliferation, and cell migration.
LLLT and Liposuction
In 2000 a new technique was introduced by Niera et al. which utilized LLLT as an adjunct to liposuction. They used a dose rate that caused no detectable temperature rise in the tissue and no macroscopic changes in the tissue structure were observed. This application of LLLT was derived from prior investigations of LLLT in wound healing, pain relief, and edema prevention. The development of LLLT was predicated on determining the optimum wavelength, and power necessary to augment lipoplasty without altering macroscopic structure of the tissue. Evidence existed that wavelengths between 630 and 640 nm were optimum for biomodulation and these wavelengths were therefore used for LLLT-assisted lipoplasty.
Neira et al. studied samples of human adipose tissue from 12 lipectomy patients who were operated with and without tumescent technique and externally irradiated with a 635-nm, 10 mW diode laser with total energy values of 1.2-3.6 J/cm2 for 0-6 minutes. The group found out that the tumescent technique had synergistic effects, facilitated laser light penetration, and intensity, thus improved fat liquefaction . While after 4 minutes of laser exposure 80% of the fat was released from the adipose cells, after 6 minutes of laser exposure almost all of the fat was released from the adipocyte. When no tumescent solution was applied and adipose tissue was exposed to laser beam for 4 and 6 minutes, scanning electron microscope (SEM) and transmission electron microscope (TEM) images after 6 minutes laser exposure in samples taken without tumescent solution corresponded to those observed in samples exposed to 4 minutes of laser irradiation with equal parameters and the tumescent solution.