Red light therapy is a healing technique that originated with lasers and morphed into “cold laser” or “low level light therapy.” With vendors making huge claims about its affect on health, how do you know what’s true and what’s a scam?
Out of 5,000 red (and blue, infrared, green and yellow) light studies in the past 50 years, the vast majority support light therapy as a reliable healing modality. Red light therapy can heal so many problems because it stimulates the body to make energy. Rather than acting on the wrinkles or acne, or pain, it stimulates the cells to make the energy required for the body to heal itself.
Cold Laser or Low Level Light Therapy (LLLT) came out of laser medicine when researchers realized that “cold” light heals. You don’t need a hot column of laser light to get the healing effects. You just need the right wavelength (color) and irradiance (power) to stimulate the body into a healing state.
Are You Looking for the Light Therapy Device Guide?
If you are figuring out which type of device to buy, I wrote a complete guide and a shortcut guide just for that purpose. Take a look here:
How Red Light Therapy Works
Our bodies absorb light in photoreceptors. When we absorb enough light of the right color, the body kicks off a cascade of healing events.
Best Red Light Therapy is dedicated to helping you figure out whether the home red light therapy device you want makes sense for your needs. That’s why I am putting the rest of this technical part of this answer at the bottom of the page. You can scroll there to read more, or you can get to the good stuff about which red light therapy device will help you with wrinkles, acne, pain, arthritis, hair growth, and fat reduction.
Why Home Light Therapy is Now So Popular
Researchers originally believed that light therapy required the power and focus of lasers beams. Lasers deliver light in columns that concentrate the beams onto a point. That point gets very hot within a short period. Lasers can blind and burn as a result.
In the 1960s, a Hungarian researcher realized that low energy lasers triggered the same healing responses as hot lasers. This led to the invention of cold lasers and the primary customers were veterinarians.
Researchers discovered healing from cold LED light. LEDs do not deliver light in columns the way lasers do. This meant that practitioners could dispense a cloud of light from an LED rather than a column of light from a laser.
For about the last 20 years, researchers have performed over 5,000 studies to test new light therapy ideas. They tested low energy laser beams, and low energy light emitting diodes (LEDs). Repeatedly they found that low energy lasers and LEDs triggered a healing response.
These studies justified investment in home-use LED light products. Red light therapy is the most popular, and usually includes both red and infrared light. Home devices emitting blue, green or yellow light are now becoming popular, as those colors have specific healing abilities as well.
What Color Light is Healing?
Infrared, red, green and blue are the most studied lights used in home therapy devices.
Red and infrared are anti-inflammatory. Infrared penetrates the deepest into the body. It helps the brain function and bones to heal. Blue light kills bacteria, and it helps reduce acne. Green light calms migraines and helps wounds to heal.
You might see purple, yellow, amber, orange and white in light therapy brochures. The sciences don’t agree on where one color ends and the next begins, so there are overlaps in the vocabulary.
“Purple” usually means blue. “Yellow,” “Orange” and “Amber” are not very well studied. They are closest to red. “White” or “broadband” indicates that several colors are shining at once. Without wavelengths, it’s impossible to know what a vendor means by “white.”
UV, UVA and UVB are ultraviolet. Dermatologists use UV light to treat psoriasis.
What Wattage is Best for Red Light Therapy?
The therapy device’s wattage does not factor into whether the device is effective. It’s the energy from the device to your skin that matters, not the energy from the plug into the device. The best way to ask this question is “What is the best irradiance for red light therapy?” The answer is anywhere from one-half of a milliwatt to 100 milliwatts.
You can judge a vendor by its irradiance statement. Red light therapy vendors have a very strong tendency to overstate the device irradiance. Presumably, if a competitor says their device outputs 100 milliwatts, then they feel they need to say their device outputs 100 milliwatts.
To achieve these measurements, vendors often use the incorrect type of meter to measure their device’s output. For example, they might use a solar meter to measure the energy coming from a therapeutic light, when solar meters overstate by double the energy coming from LED devices. Solar meters are calibrated to the sun, not to light emitting diodes.
UV is not available in home light devices because it is dangerous to the eyes and skin. Blue and infrared can harm the eyes but are available in home devices. UV is more dangerous.
An Easy Trick to Discover the Light Device’s True Irradiance
The easy way to tell the real light irradiance (output power) is to check the treatment time per session. A powerful device delivers a dose in 30 seconds to 10 minutes. A medium device delivers a dose in 10 to 20 minutes. A weak device takes 20 to 30 minutes per session.
Use those treatment times as your guide when looking at red light therapy specifications. Due to marketing pressures, vendors overstate irradiance, making it difficult to compare red light therapy apples to red light therapy apples.
It doesn’t matter what the stated irradiance is. The truth is in the treatment times. Using this trick, you can avoid the 100 mW/cm^2 jargon altogether. Should you want to learn how to read irradiance, though, please enjoy my articles on EMF Channel: Irradiance Definition and What is a “Dose” of Red Light Therapy?
Is Red Light Therapy a Laser?
Red light therapy can be a laser or some other form of light. LEDs usually light at-home therapeutic devices. Both lasers and LEDs can output the light the body finds therapeutic.
In the beginning, there were only lasers. When researchers discovered getting equivalent results with LEDs, the science and the markets both opened up to new products. LEDs are cheaper and safer than lasers. That means the functionality that used to be only from lasers is now available in home products.
Are Cold Lasers as Effective as “Hot” Lasers?
The photons of light energy do the healing. Not how fast they get there or how energetic (hot) they are on arrival. Lasers produce photons. LEDs produce photons. Both send healing photons to the body.
A laser output beams of light in one direction. Those beams converge on a spot. The concentration of light is hot enough to burn the skin or blind an eye. That is why we have not had “at home” light therapy with lasers.
An LED sends out light in several directions. The beams do not converge on one spot. They are not hot. They don’t burn anything. LED light is safe because it is “cold.”
The issue is not 100% settled. We don’t yet have absolute proof that anything you can do with a laser you can also do with an LED. Thousands of studies show that LEDs are as effective as lasers. (source)
Red Light Therapy Works on Aging
Low Level Light Therapy (LLLT) is “possibly the ultimate non-invasive approach to treating the skin.” – Dr. Michael Hamblin
There are many benefits to using infrared, red and blue light therapy on the skin. There are no known negative side effects. Red light therapy increases collagen, reduces wrinkles, reduces sagging, evens skin tone, and smoothes pigmentation.
Use Red and Infrared Therapy to:
- reduce wrinkles
- reduce redness
- reduce inflammation
- reduce psoriasis and acne
- reduce fine lines
- reduce pigmentation*
- increase vitiligo skin pigmentation*
- reduce age spots
- reduce photodamage
- improve skin texture
- improve skin firmness
- increase lymphatic system activity
- heal non-melanoma skin cancer
- rejuvenate skin
- speed wound healing
- protect from UV sunburn
- treat UV exposure
*If red light increases unwanted pigment, ensure you are not getting infrared heat. If the light is cool and the situation continues, discontinue infrared light.
Use Yellow/Amber/Orange Light Therapy to:
- reduce wrinkles
- reduce fine lines
- reduce inflammation
Red and infrared light reduce fine lines and wrinkles. They stimulate collagen and elastin, which fill out creases.
In a study of 76 patients, researchers gave red, infrared, or a combination to one-half of each participant’s face. Wrinkles reduced by as much as 36%, and elasticity increased by as much as 19%. The red, the infrared, and the combination group had similar gains. (source)
In another study testing red light in vitro, researchers found that red light alone reversed collagen downregulation, meaning that the skin produced more collagen than normal. Collagen reduces wrinkles and fine lines. (source)
A third study tested the effect of blue, red and/or infrared on the lymph system. They found that stimulation with any of these lights increased lymphatic system activity. That activity correlated with reduced wrinkles, reduced hyperpigmentation, enhanced glow, increased collage and decreased acne. (source)
Infrared, Red, Blue and Green Light Therapy Work for Acne
Multiple studies using blue, red, infrared, or some combination of these lights show that light therapy heals acne.
Blue light reduces inflammation and kills bacteria. The result is reduced oil and pimples.
Green and blue light kill the bacterium P. acnes, one of the causes of acne. Red and blue combined significantly reduce acne symptoms.
In one study testing blue and red light, blue light, white light, and benzyl peroxide, researchers found that the combination of blue and red light had the greatest ability to reduce acne lesions. The group receiving blue and red at the same time had a 76% reduction in inflammatory lesions. (source, source).
Another study included both blue and red, but treated patients with each color on different days. One day they got red light treatment, and the next session they got blue light treatment. 22 patients receiving alternating red and blue therapy saw an 81% lesion reduction at 12 weeks. (source, source)
In a study of red and infrared without blue light, researchers found that red light had a significant ability to reduce acne, but that infrared light did not. (source)
In one study, researchers treated acne patients with two wavelengths of red light: 635 nm and 670 nm. The patients got a very low dose of energy per session, but they got 112 treatments over a 2-month period (2 times a day for 8 weeks). At the end of the study, the acne blemish count fell 51%. (source) (source)
I’ve put more acne studies in the EMF Light Therapy Dose Database that you can view at this link (opens in a new window).
Red Light Therapy Can Heal Some Eye Conditions
WARNING: Many vendors, enthusiasts and researchers dismiss concerns about eye damage using light therapy. Blue light certainly can harm the eyes. Infrared can cause cataracts over the long term. I err on the side of caution. Talk with your ophthalmologist before exposing your eyes to light therapy.
Red light therapy can enhance an older person’s ability to see color. Older eyes lose the ability to distinguish colors. This is not a disease but just a normal part of the body tiring out with age. The part of the eye that perceives the color blue loses strength with age.
Eyes lose the ability to make energy. The mitochondria are responsible for producing energy. The mitochondria in the eyes tires out. Red light specializes in inducing the mitochondria to make energy. Therefore, red light therapy is a perfect fit for tired mitochondria in the eyes.
In one study, patients received 670 nm red light to the dominant eye. One group was under 40. The other group was over 40. The young people did not experience changes in vision. The people over 40 years old gained back their ability to distinguish the color blue.
Red Light Therapy Works for Pain Relief
Red light therapy has an anti-inflammatory and an analgesic affect on pain. The inflammation reduction reduces pain triggers. The analgesic affect numbs the pain.
Researchers tested red light therapy on breast augmentation patients. Doctors shined 635 nm red light at the incisions while the patients were still on the table. The light doses were relative low.
Patients did a self-assessment 24 hours after surgery. 76% of the patients who had received red light treatment reported at least 30% less pain than the control group. These patients asked for less pain medication too.
Red Light Therapy Works for Hair Growth
Red light therapy helps hair to grow in many types of baldness, but not all types.
In one study, researchers gave balding patients high doses of red light. They received three shades of red: 630 nm, 650 nm and 660 nm. Each patient was treated for 168 days. All patients grew hair by the end of the 24 week (6 months) period. Their hair was thicker and denser than at the start of the study.
In another study, balding women were treated with one shade of 655 nm red light. Each patient received 60 treatments of high dose red light over 16 weeks. On average, the treated women grew 37% more hair than the women in the untreated control group.
Red Light Therapy Can Melt Fat
WARNING: Note the protocol you have to do for this to work. It’s not an automatic freebie!
Red light therapy can induce cells to open micropores through which the triglycerides fall into the spaces between the fat cells. If the user exercises immediate after treatment, she can shed the loosened fat through the lymphatic system. The FDA allows this process in commercial treatments, so it is a proven concept.
It is often not as easy as it sounds. It helps not to eat prior to the session, and exercise after light therapy is required. If you point red light at fat and it does not reduce, look at the eating and exercise schedule. In addition, drink water after therapy to flush the system.
In one study researchers treated patients’ fat with 635 nm red light. The lights were embedded in wraps around the patients’ arms. The dose was relatively low. After two weeks and six sessions, the patients’ arm size reduced from losing fat. Arm sizes dropped an average of 3.7 cm, or 1.4 inches.
In the original study showing how red light affects fat, researchers looked at treated fat cells under an electron microscope. They took pictures of the deflated fat cells that had just let go of their fat and water. It took only a relatively low dose of 635 nm red light to release the fat during a single treatment.
Can You Use Red Light Therapy Every Day?
In many situations, you can use red light therapy every day. Some successful anti-aging and anti-acne studies applied light therapy daily. The majority of studies spread out the treatments to two or three times per week.
For example, this study tested a combination of blue and red light on mild to moderately severe acne. Patients received treatment only twice per week for 4 weeks. The group experienced a mean average non-inflammatory lesion reduction of 34.28%, and a mean average inflammatory lesion reduction of 77.93%.
While you can use red light therapy every day, you might get just as good results doing it less often.
The device you buy for at home use should include the answer to this question. People engineering the lamp know its specifications. They should be familiar with the dosing paradigm to make good recommendations to their customers.
How Long Should You Use Red Light Therapy?
Light therapy is a Goldilocks treatment. Too little or too much are the same as not doing it at all. The dose has to be just right. More is not better. If you know how (or want to learn how) to calculate dosing, you will need to know your device’s specifications. You can get the information on how to dose on my site EMF Channel: What is a Dose of Red Light Therapy? (Opens in new window)
If you don’t want to learn the irradiance, wavelengths, time and distance parameters of light dosing, go by the instructions on your device. No one knows better how to use a light therapy device than the manufacturer.
Can You Overdo Red Light Therapy?
Too much red light therapy can result in making things worse, or just reversing gains achieved to that point where the overdose started. Once the cells fill up with light, the positive response reverses. This usually results in it appearing as if the light is not helping. In fact, it’s not proof of that at all. Improper dosing will stop the healing effects of light therapy.
What Time of Day is Best for Red Light Therapy?
Blue light therapy should be done in the morning. Blue light suppresses melatonin. You need that to feel sleepy, so you don’t want to suppress it at night.
The other colors of green, yellow, red, and infrared can be done at any time. Some people feel no difference using light at any time of day. Some people respond best in the morning, and some at night. The effect is about your biology and response rather than there being a rule as to when to do therapy.
Can You Wear Clothes During Red Light Therapy?
You cannot wear clothes during red light therapy unless you are OK with not getting treatment where the clothes block the light. For face treatments, for example, you can wear clothes because you are not treating your body. Light therapy does not penetrate clothing.
How Long Does it Take to See Red Light Therapy Results?
In the acne study we mentioned earlier, patients received treatments two times per week for four weeks. They experienced a reduction of 34% to 78% inflammatory lesions at 8 weeks. It did not all get better at 8 weeks, that is just when researchers measured results.
In this wrinkle reduction red light study, researchers treat patients with light therapy daily for 12 weeks. The tested group had a significant reduction in wrinkles measured at that point.
In another study of red and infrared for wrinkle reduction on the neck rather than the face, patients received daily treatment for 16 weeks. Wrinkle reduction was significant at 16 weeks when measured.
In a study of infrared applied up the nostril and on the scalp, dementia patients received infrared light therapy for 12 weeks. Both mild and moderately severe dementia patients experienced significant cognitive improvement when measured at 12 weeks.
In a case study of one combative dementia patient, treatment was just two days before significant changes occurred. After two days of infrared and red light treatment through the nose, cognition improved, sense of smell returned, memory scores improved, and stress reduced.
In measuring the blood flow in the head, 6 sessions of red light treatment over 3 weeks resulted in increased blood flow in three cerebral arteries.
Is Light Therapy Like Being in the Sun?
Red and infrared light therapy includes some of the wavelengths that we get from the sun. Only light therapy at a dermatologist’s office includes ultraviolet (UV). UV rays are effective for problems such as psoriasis, but UV is dangerous to the body.
Red light therapy never has ultraviolet rays. The closest it comes is blue light therapy.
Blue light is next to UV on the electromagnetic spectrum. Blue light suppresses melatonin and can cause insomnia. Blue light can damage the eyes.
Can You Tan and Do Red Light Therapy on the Same Day?
Tanning is dangerous and probably should not be done, but if you want the answer: no, you should not do red light therapy and tanning on the same day. Red light is protective against ultraviolet. The theory is that the photoreceptors fill up on red photons, which blocks the UV photons from entering the skin. Red light therapy acts like a sunscreen that protects your skin from tanning and burning.
Does Red Light Therapy Give You Vitamin D?
The body produces Vitamin D when exposed to sunlight’s ultraviolet rays. Red light therapy does not have UV and does not induce the production of Vitamin D.
Can You Get Red Light Therapy from the Sun?
You can get red and infrared wavelengths from the sun. Whether this is therapeutic depends on how much of your skin absorbs that light. These wavelengths are easiest to get in the morning and evening sun, and not in the mid afternoon.
Do Red Light Tanning Beds Work?
Just to be abundantly clear, red light therapy does not tan. The red light beds that look like tanning beds do not emit ultraviolet light. UV is dangerous, and tanning beds are dangerous.
Many Planet Fitness members speak highly of the Beauty Angel red light treatment there.
Can You Just Use a Red Light Bulb for Red Light Therapy?
Light bulbs have two problems that prevent them from being therapeutic. Their light is scattered, so only a portion will reach the target. In addition, they put off quite a bit of heat. You do not want heat. You want photons. I have talked to many biohackers. I do not know of one who has successfully repurposed a light bulb for red light therapy.
Is Red Light Therapy Safe?
Light therapy with LED home devices is safe with a few exceptions mentioned below. Light therapy performed with lasers is dangerous without proper safety procedures.
The FDA designates the low power laser treatment of pain a “nonsignificant risk” for human testing. LEDs are cool to the touch. Low power laser also means Low Level Light Therapy and LED Light Therapy.
LED light therapy:
- does not require drugs
- does not heat the skin (the light heals, not heat)
- is non-invasive
Light Therapy Cautionary Contraindications
An abundance of caution dictates the following people not do light therapy without physician consultation:
- pregnant women
- nursing mothers
- epileptics and those with seizure disorders
- people on photo sensitive medications
- people with tumors (controversial, as LED therapy significantly helps with radiation treatment side effects)
What are the Side Effects of Red Light Therapy?
Blue light decreases melatonin and can damage the eyes. As long as the user wears a complete eye covering, blue light therapy has neither of these side effects.
Infrared light is helpful for pigmentation issues, but can also sometimes cause unwanted pigmentation. If this occurs, stop use of infrared, and add blue if possible.
If there is any chance that you are getting heat from the infrared, create more distance between the device and the skin target. The light heals, not the heat.
Is Red Light Therapy Bad for Your Eyes?
Blue light is harmful to the eyes. Users should wear blackout goggles when doing blue light therapy.
Whether infrared light therapy is harmful to the eyes is controversial. Long-term infrared exposure causes cataracts.
Do You Need Goggles for Red Light Therapy?
Certainly many studies show that red and infrared heal macular degeneration and low vision. These studies do not establish a safety profile either. I tend to err on the side of caution. Assume the worst and take precautions.
How Can You Protect Your Eyes from Red Light Therapy?
Wear goggles to protect your eyes from blue, red and infrared light therapy. I am a fan of GembaRed light therapy because its management is honest to a fault. We differ somewhat on our understanding of eye health. Nevertheless, Andrew LaTour offers a comprehensive guide to light therapy eye protection. Check out GembaRed’s Is Red or Infrared Light Dangerous for the Eyes? – Eye Protection Guide Part 1, and Top RED & NIR Blocking Eyewear, Goggles, Sunglasses, and Safety Glasses Reviewed! – Eye Protection Guide Part 2
Is Light Therapy Safe for Dogs?
Light therapy is safe for dogs, cats, horses and all mammals, as far I can tell. Light therapy was a veterinarian treatment for dogs long before the home devices came on the market for humans. Dogs respond to red and infrared with lower inflammation and pain relief. Red light therapy is popular with horse owners.
Treatment times might be shorter for dogs than for humans. If you are unsure, you can do more minutes each day until you reach the human dose. An easier way to handle the dose issue for dogs is to buy a cold laser designed for animals.
How Red Light Therapy is Therapeutic
We have photoreceptors in our skin called chromophores. The chromophores have maximum sensitivity to absorbing red and infrared light. The Red and infrared energy
- skin cell mitochondrial chromophores absorb photons
- electron transport increases
- nitric oxide increases
- adenosine triphosphate (ATP) increases
- blood flow increases
- reactive oxygen species (ROS) increases
- signaling pathways activate
- can activate stem cells which repair tissue
Red and infrared light therapy creates an energy-production cascade of events. Photoreceptors in the body’s energy-making mitochondria absorb the light. When enough photons reach the cells, the body goes into energy production mode. The result is more energy and nitric oxide. Blood flows easier, and brings oxygen and nutrients to areas that need it.
Researchers also believe that light therapy triggers the body’s messaging systems. DNA kicks off protein creation. Light therapy triggers the body to create amino acids that form proteins, which are the building blocks of life.
Blue light causes a DNA messaging mechanism to clog. It stops signaling, and after a long chain of events, unhealthy cells die off. This is why blue light is good for acne, especially when that acne involves the P. acnes bacterium.
To learn more about the photochemistry and photobiology of light therapy, see my article Is LED Therapy Effective? Yes. Yes it Is. (study summary)
How Red Light Therapy Works for So Many Health Concerns
Red light therapy stimulates the energy production in the cells. The photoreceptors absorbing the light photons are inside the mitochondria. The mitochondria are inside the cells. When the photoreceptors absorb a sufficient amount of light, the body makes energy, increases blood flow and delivers oxygen and nutrients nearby. This is why red light therapy is successful at treating so many conditions. It’s giving the body the energy it needs to heal itself.