How Does Red Light Therapy Work? Mitochondria Power
If you ask, “How does red light therapy work,” you’re not alone.
Red light therapy is exploding in popularity, but it’s so new you have many questions.
Did you know that red light therapy can clear acne and reduce wrinkles and pain?
It’s all done with a device you can use without a doctor’s prescription at home.
Takeaways
- Photobiomodulation (PBM) or red light therapy uses specific wavelengths of light to trigger cellular repair mechanisms
- It works by absorbing red/near-infrared light in mitochondria, increasing ATP and reducing oxidative stress
- Has biphasic dose-response – too little or too much light is ineffective, optimal “therapeutic window” exists
- Produces reactive oxygen species (ROS) but also antioxidant effects to resolve them
- Clinically proven to reduce pain inflammation, and promote tissue healing/regeneration
- Both lasers and LEDs can deliver effective PBM doses, with differing power levels
- Generally very safe with over 1,000 supportive clinical studies
How Red Light Therapy Works, According to Science
Dr. Michael Hamblin is the reason you’re hearing about red light therapy.
He has written hundreds of papers detailing how light affects biology in his roles at Harvard, MIT, and the University of Johannesburg.
In a 2018 paper, Dr. Hamblin explained how red light therapy works by citing the “mitochondrial redox signaling” hypothesis.
Two hypotheses exist about how red light therapy (photobiomodulation or PBM) works.
- Hypothesis 1: The Redox Theory is that light is absorbed in the mitochondria at the cytochrome C oxidase (CCO). Inhibitory nitric oxide disassociates from CCO. This increases the mitochondrial membrane potential.
- Hypothesis 2: PBM activates gated ion channels through a heat and/or a light pathway.
This paper reviews the Redox Theory of the effects of photobiomodulation.
“Photobiomodulation (PBM) involves the use of red or near infrared light at low power densities to produce a beneficial effect on cells or tissues. PBM therapy is used to reduce pain, inflammation, edema, and to regenerate damaged tissues such as wounds, bones, and tendons.”
– Dr. Michael R. Hamblin
Laser Medicine that Does Not Use Lasers
The term “laser medicine” became inaccurate when researchers were able to achieve the same effects with non-laser lights.
Lower-power light-emitting diodes (LED) can create the same mitochondrial and healing changes as higher-powered laser lights.
LLLT as Low-Level Laser
Journal authors renamed “laser medicine” to “low-level laser therapy.” That would be fine if an LED were a low-level laser, but it is not. Lasers emit coherent waves. LED emits incoherent waves. Calling an LED a “low-level laser” just confused the issue.
LLLT as Low-Level Light
The authors recognized that LEDs are not low-level lasers, so the authors changed LLLT to mean “low-level light therapy.”
Now, there were two problems.
First, previous authors used LLLT to refer to low-level lasers. LLLT would bring up laser and LED studies when searching scientific journal databases.
LLLT had two meanings, which confused researchers.
Next, “low-level light therapy” completely drops “lasers,” which is not what we are trying to say.
We are trying to describe the use of light in medicine, whether that light comes from LED or laser sources.
Photobiomodulation: Using Light to Change Biology
A few light and laser medical organizations agreed. In 2016, they officially changed laser medicine, low-level laser therapy, and low-level light therapy to Photobiomodulation (PBM).
PBM uses photon (light) energy to change (modulate) biology.
Photobiomodulation is over 50 years old. Researchers first applied the concepts to wound repair on the skin and in dental procedures.
Researchers initially found success using 694 nm and 633 nm wavelengths, both of which are red. Repeatedly, researchers found frequencies in the red (and infrared range) to heal human and animal biology.
What we now call “Red Light Therapy” (RLT) is the same as “photobiomodulation.” RLT is the commercial term, and PBM is the scientific term.
Laser and LED Effectiveness
Clinicians and consumers can treat scores of problems with light. Researchers have repeatedly found LEDs to be as effective as lasers.
Lasers are more powerful and take less time to deliver their effective dose.
Clinicians use both laser and LED devices, while consumers use LED only. Lasers can burn, so they are not consumer devices.
Laser and LED lights are equally effective.
Lasers are more powerful, so treatments are faster. LEDs are cooler, so treatments are slower, but consumers can do them at home.
Photobiomodulation Success and Safety
Over 1,000 clinical studies show that PBM is healthy and generally very safe.
PBM is a Goldilocks therapy. The dose must be just right, or the recipient will not get a healing response.
This is because Photobiomodulation has a “biphasic dose-response” that follows the “Arndt-Schulz Law.”
The biphasic dose response means that:
- A little bit of energy does not work.
- Too much energy does not work.
- The healing dose of energy is in a sweet spot between too little and too much.
- The effectiveness plateau is a range of energy in the sweet spot, and all energy levels within this range have healing effects.
The First Law of Photobiology
For PBM to be effective, the chromophore molecules in the mitochondria must absorb the photons. This is the first law of photobiology.
For example, when the chromophore molecules absorb red nm (nanometer wavelength) photons, the molecules initiate a chain reaction that disassociates nitric oxide, leaving the mitochondria with more oxygen. This gives the body more energy.
The chromophore’s ability to absorb light changes with the light’s wavelengths. Therefore, some wavelengths are more effective than others.
Mitochondrial ATP production creates a healthy response in skeletal muscle, cardiac muscle, neurons, liver cells, kidney cells, and more.
PBM Redox Increases Energy and Absorbs Oxidants
PBM affects reactive oxygen species (ROS).
We usually think of ROS as free radicals, but PBM can use them as messenger transports.
Light in the blue color range has the most significant ROS impact because it induces ROS creation without reducing their impact.
Red light induces ROS but resolves its presence before it can harm the body.
When red light produces reactive oxygen species, the mitochondria absorb them. Red light increases energy (ATP), which gives the body’s system energy to heal.
The red light absorption process invokes N-acetylcysteine, which, in turn, reduces reactive oxygen species.
Thus, red light produces free radicals but disarms them. Red ROS are mediators.
Blue light produces free radicals; at least in some cases, those reactive oxygen species harm the body.
Biphasic Dose Response
PBM can both heal and harm. Dose quantity and frequency determine the biological response.
For example, 780 nm at 50 J cm^2 (infrared light delivered in 50 joules per square centimeter) increases bone tissue to act on osteoporosis and fractures that fail to heal positively.
On the other hand, 650 nm at 50 J cm^2 (red light delivered in 50 joules per square centimeter) decreases bone tissue, worsening osteoporosis and joint failures.
PBM has a protective effect at multiple levels. For example, 670 nm (red) LED reduces methanol and potassium cyanide neural damage. When the tissues are exposed to 670 nm light before cyanide exposure, the cyanide cannot kill as many cells (the light reduces apoptosis).
Red light therapy works at least in part through Redox Signaling.
- Photobiomodulation (PBM), also known as red light therapy, works by absorbing specific wavelengths of light in the mitochondria, which triggers a series of biological reactions.
- The main hypothesis (Redox Theory) is that red/near-infrared light is absorbed by cytochrome c oxidase (CCO) in the mitochondria, which increases ATP production and promotes healing.
- PBM has a biphasic dose-response, meaning too little or too much light does not produce the desired effects. The optimal “therapeutic window” lies between these extremes.
- Red light produces reactive oxygen species (ROS) but also triggers antioxidant mechanisms to resolve them, acting as signaling molecules to promote healing.
- PBM is generally safe and is effective in over 1,000 clinical studies for reducing pain, inflammation, and edema and promoting tissue regeneration.
- Both lasers and LEDs can deliver effective PBM doses, with lasers being more powerful for faster treatments and LEDs being safer for at-home use.
- The wavelengths most commonly used are in the red (630-700nm) and near-infrared (800-850nm) ranges, as the mitochondrial chromophores best absorb these wavelengths.
In summary, PBM utilizes specific light parameters to trigger beneficial biochemical reactions in the mitochondria that reduce oxidative stress and inflammation while increasing energy production and cellular repair mechanisms.
Red light therapy supplies the cells with energy from specific wavelengths of light.
The cells use this energy to make biological batteries (ATP or adenosine triphosphate), release nitric oxide (which opens blood vessels), and signal the immune system to stop chronic inflammation.
- The light travels through the skin to the cells
- The mitochondria in the cells absorb the light
- The electron transport chains in the mitochondria use the light energy to create adenosine triphosphate (ATP). The cells use ATP for:
- autophagy (cellular cleanup)
- mitophagy (mitochondria cleanup)
- synaptogenesis (creation of new connections between cells)
- neurogenesis (creation of new brain cells)
- cell turnover (production of new skin cells)
- The electron transport chain releases nitric oxide that:
- dilates the blood vessels
- triggering more blood flow to injured areas
- bringing oxygen and nutrition to those areas
- the blood, along with ATP, allows the tissue to self-repair
- The mitochondria signal the immune system to stop sending inflammatory chemicals, which lowers inflammation and pain.
Types of Red Light Therapy at Home
Red light therapy is much more than red light.
Potential benefits come from many colors including red, green, blue, and yellow, as well as the mostly-invisible infrared.
Devices come in panels, wands, pads, hats, and many more designs
The type of light you get to use red light therapy will depend on the potential benefits you seek.
For instance, you might use a panel for exercise recovery and soft tissue injury; a pad for fat loss therapy; or a face mask for acne or wrinkles reduction.
The Potential Benefits of Red Light Therapy
Potential benefits, if you use red light therapy (also known as low-level laser light therapy), include:
- Reduced acne
- Reduced psoriasis
- Reduced eczema
- Skin rejuvenation
- Reduced fine lines and wrinkles
- Smoother skin
- Reduced melasma (pigment disorder)
- More hair
- Less fat
- Better vision
- Reduced pain and inflammation
- Faster wound healing
- Decreasing symptoms of brain injury and dementia
LED light therapy is used in clinical settings, as is low-level laser therapy, low-power red light, low-power laser therapy, or photobiomodulation.
Dermatologists and hair clinics use red or near-infrared light to grow hair and reduce wrinkles. They use blue, infrared, and red light wavelengths to minimize acne.
The same red light therapy used in clinical settings is now available for you to do red light therapy at home.
Studies on red light therapy show that potential benefits last for months or even years.
The Side Effects of Red Light Therapy
According to thousands of studies, red light therapy has no side effects.
As of November 2022, Dr. Vladimir Heiskanen has documented journal papers about red light therapy.
He found 6,380 papers, and in my search, I’ve discovered over 9,000 papers:
- 2,180 human studies
- 1,980 animal studies
- 1,220 in vitro studies
- 640 narrative reviews
- 360 systematic reviews
The mention of side effects is almost entirely missing from these papers, but there are a few exceptions.
In a few studies I’ve read, I found that red light therapy may cause mild headaches and reddened skin from using red and infrared light.
Certainly, the safety profile is superior to that of acetaminophen, which has side effects including rash, itching, swelling, and difficulty breathing.
I’ve read hundreds of studies and have never seen anything close to the severity of something “safe.”) (Tylenol), which is more likely to cause side effects.
Using red and near-infrared light (green, blue, and yellow) is noninvasive, drug-free, and has next-to-zero risks or side effects.
It cannot burn the skin or even cause damage to the skin.
None of the painful side effects from drug remedies happen when you use red light therapy.
Of course, people on light-sensitive medications and epileptics should avoid red light-emitting devices, but that is a unique and very small subset of potential users.
The mention of side effects is almost entirely missing from these papers, but there are a few exceptions.
Red light may help you:
Should You Get Red Light Therapy?
If you have seen the claims and thought, “How is this even possible? Is this a scam?” you are not alone.
Infrared, red, blue, green, and yellow lights are remarkably powerful when used correctly.
How did we not know about this before?
Lasers.
Until recently, only doctors could get these results from red lights because they used lasers that were off-limits to home users.
Now that we know that cheaper LEDs work as well as lasers, the positive effects are now available as at-home red light devices.
Lasers are dangerous, they can burn and blind you, so you can’t just get a class IV laser light to treat skin.
A researcher accidentally discovered he could get the same results with less powerful lights than lasers.
This was in 1967, so what took so long?
Scientists have tested this theory over 5,000 times and published results in scientific papers.
An important paper came out in 2000 in which NASA verified that LEDs worked well as therapy for wound healing in Navy SEAL volunteers.
This is when the possible benefits of red light at home became a reality.
LEDs don’t hurt the eyes, which means there is now a consumer market for the healing energy of red, blue, and yellow light.
The market is now reaching critical mass, which is probably why you’re reading my blog!
How You Absorb Light From a Red Light Device
The skin is better at absorbing some wavelengths of light.
The good news is that you can still get a significant effect despite imperfect absorption.
Some of the light will get lost in reflection or turn into heat.
But the light that heals will travel to the cells inside your body (and brain).
Inside those cells are mitochondria, responsible for making the biological batteries that run the body.
The photons (light packets) lend energy to the battery-making process, which produces twenty or 30 biological events with healing effects.
(This is why the scientific term for red light therapy is “photobiomodulation.”)
The light kicks the self-healing mechanisms into high gear.
It causes the mitochondria to message the cell to stop chronic inflammation, eliminate old cells, and improve blood flow.
This happens inside the mitochondria, which send messages and chemicals throughout the body to create healing responses.
LED lights work just as well as lasers at healing the body. If you are trying red light therapy, it is more economical to acquire an LED device than a laser.
Light always could do these marvelous feats of healing.
However, only doctors were allowed to use the lasers.
LEDs don’t hurt the eyes, which means there is now a consumer market for the healing energy of red, blue, and yellow light.
If You Get Nothing Else, Understand This
- Light heals if you get the right kind of light in the right amount.
- The efficacy of red light therapy is proven in over 9,000 studies.
- The amount of light is like your “dose” of red light energy.
- If a lamp is too weak, or you spend too little time with it, or you spend too much time with it, you will not get a healing result.
You will be successful if you follow these rules:
- Get the right kind of light (the suitable wavelengths)
- Get enough power (the lamp can’t be too weak)
- Get enough energy (spend enough time per session)
- Please don’t get too much energy (it’s hard to do with home devices, but don’t spend too much time per session)
Can I Use a Light Bulb Instead of a Therapy Device?
A light bulb would unlikely give you enough of the right light to help you heal.
You are welcome to try, though, if you want to experiment.
You need two things to make a therapeutic lamp:
- The right amount of energy
- The correct wavelength of light
Household light bulbs are very low-power devices.
There is no assurance that a red light bulb emits the right red light.
There is no science saying you can and no science saying you cannot.
There is no harm in trying.
How Does Light Therapy Help So Many Issues?
The secret to the scientifically cited benefits of red light lies in the electron transport chain, the mitochondria, and the cell.
Researchers believe they are getting these excellent results because red light lends massive amounts of energy to the mitochondria.
After light penetrates the layers of the skin, its energy helps open blood vessels, take out toxic garbage, and supply energy for self-healing.
On top of the energy production, light therapy triggers at least four other health responses.
Healthy red light wakes up the body’s messaging systems.
The messengers ultimately reach the DNA, where powerful healing is possible.
Scientists speculate that DNA kicks off the creation of proteins. This means that the light triggers the body to put together the building blocks of life.
That, in turn, reduces inflammation, prevents protein cell death, and turns on the anti-oxidants to protect the body from rusting out. (source)
How Does Light Heal?
The body absorbs certain types of light. It uses the energy from the light to repair your body’s tissues. Just as plants use light to grow, humans accept light to heal.
The body has about five responses to healing light. The best understood is the energy creation response.
Our skin has wavelength-specific light receptors. The receptors grab the light’s energy and hold onto it.
The energy accumulates until it reaches a boiling point. All at once, the energy factories start cranking out the chemicals the body uses to function.
That energy brings blood, oxygen, and nutrients to wounds. It wakes up hair follicles to start making hair again.
It induces fat cells to let go of their contents.
How is Red Light Such a Powerful Treatment?
Researchers believe they get these excellent results because red light wakes the body’s energy factories.
When the body receives enough of the right light, it starts pumping out energy chemicals everywhere.
The energy takes the form of blood and oxygen, reaching and repairing damaged areas.
On top of the energy production, light therapy has triggered at least four other health responses.
Healthy red light wakes up the body’s messaging systems.
The messengers ultimately reach the DNA, where powerful healing is possible.
Scientists speculate that DNA kicks off the creation of proteins. This means that the light triggers the body to put together the building blocks of life.
That, in turn, reduces inflammation, prevents protein cell death, and turns on the anti-oxidants to protect the body from rusting out. (source)
What Does Red Light Heal?
Red Light has a fantastic record of accomplishment in the lab.
It heals wounds, fractured bones, and wrinkled skin.
It grows hair on bald men and women.
Red light can reduce pain, improve eyesight, and melt fat.
Acne
While blue light is best for acne, red light can also help clear the face.
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 2 months (2 times a day for 8 weeks).
At the end of the study, the acne blemish count fell by 51%. (source) (source)
In the following study, patients got much energy per treatment but fewer (16) treatments overall (2 times a week for 8 weeks).
The patients received red light in the 630 nm to 700 nm range.
Once again, the red light significantly reduced the patients’ acne. (source) (source)
Hair
In one study, researchers gave balding patients high doses of red light. Light therapy can help grow hair in many types of baldness.
Red light therapy may affect the follicles if they are dormant rather than dead.
The patients received a high-energy dose of 630 nm, 650 nm, and 660 nm light per treatment.
The patient’s hair grew again after 168 treatments (1x day for 24 weeks).
The hair was thicker and denser than when the study started.
Another study treated balding women with 655 nm light.
The patients got a relatively low dose of energy each session.
They got light treatment every other day for 16 weeks (60 treatments).
On average, they grew 37% more hair than the untreated women in the control group.
Red light therapy is considered a staple office treatment to grow hair now available for at-home use.
Light therapy is a treatment commonly found in hair clinics and dermatologist’s offices.
(source) (source) (source) (source)
Fat
Red light really can melt fat.
According to studies, red light therapy triggers fat cells to remove their contents.
Before I tell you more, you must understand how this works to take advantage of it.
First, do not eat two hours before a fat-burning treatment.
Next, use the light on the area of fat you want to lose.
Third, exercise right after the light treatment.
You can do 10 minutes of rigorous work or 30 minutes of light work.
If your gym has a vibration machine, you can use that instead of exercising.
You have to shake the released fat cells out of the area.
If you don’t exercise, the fat cells will reabsorb the fat.
In one study, researchers treated patients with 635 nm light.
The patients received light from LED lamps embedded in wraps around their arms.
They received relatively low-energy doses of light.
After two weeks of 3 sessions per week, the patient’s arm size was reduced due to fat loss.
Their arm sizes fell an average of 3.7 cm, 1.4 inches.
That was just from a light wrap they used 6 times in two weeks.
In another study, researchers examined the treated fat cells under an electron microscope.
They took pictures of the deflated fat cells that had just released the contents.
After only one treatment, a relatively low energy dose of 635 nm (red) light induced the fat release.
Eyes
Older eyes can lose the ability to see color.
This is not a disease like macular degeneration or cataracts.
Vision loss is a normal part of aging. The eyes tire out.
The part of the eye that perceives the color blue loses its strength as we age.
It loses the very energy-making machinery that red light knows how to trigger.
Researchers used red light (670 nm) to treat the dominant eye of younger and older patients.
The red light did not affect the younger subjects’ vision.
For people over 40 years old, it made a difference.
They regained the ability to distinguish blue, which they had lost due to aging.
Pain
Researchers tested red light’s ability to reduce pain. They tested the light on breast augmentation patients.
While the patients were still on the operating table, the doctors shined a 635 nm red light at the incision areas.
The total energy absorbed was a relatively low dose.
24 hours after surgery, patients took self-assessment questionnaires.
76% of the patients who had received the red light treatment reported at least 30% less pain than the control group.
These patients asked for and took less pain control medication as they healed.
Conclusion
Red light therapy employs different light colors (red, infrared, blue, yellow, and green) to provide various health benefits, including clearing acne, triggering collagen production, wound healing, bone repair, and reducing Alzheimer’s symptoms.
Thousands of studies validate the therapeutic benefits for skin issues, chronic pain, and faster healing.
The therapy was initially exclusive to the medical profession due to the potential harm lasers could cause to the eyes.
With the discovery of LED lights offering the same benefits, they’re now accessible to consumers.
The effectiveness of therapy depends on the type and amount of light used – too much or too little can impact the healing process.
Ordinary light bulbs are unlikely to provide the same healing benefits as they may not provide the right kind and amount of energy.
The human body can absorb certain types of light to aid in tissue repair, much like how plants use light for growth.
The absorption of light energy in the body can stimulate energy factories to produce healing chemicals, which can also enhance blood flow and nutrient delivery to wounds.
Therapy can stimulate the body’s messaging system, reaching the DNA level, where the creation of proteins can aid in healing, inflammation reduction, and antioxidant production.
Therapy has shown positive results in treating conditions like wounds, bone fractures, wrinkles, hair loss, and obesity.
It can also improve vision and relieve pain.
Red light therapy can improve color vision in aging eyes by triggering the eye’s energy-making machinery.
Red light therapy has been tested and proven to reduce post-operative pain in breast augmentation patients.
