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Red Light Therapy For Chronic Pain: The Science Behind Why It Works

Last Updated on February 1, 2023

Red light therapy can offer chronic pain relief, without the use of drugs and with zero side effects. It’s been shown to relieve pain, reduce inflammation, and more.

Pain sucks.

It’s the worst feeling in the world. And, it’s heartbreaking when you can’t do the things you used to love.

But, chronic pain doesn’t have to rule your life.

In today’s article, I’m going to teach you about the benefits of using red light therapy for pain relief. You’ll also learn the science behind how and why it works.

Chronic Pain: A Misunderstood Problem

If you have chronic pain, you know how debilitating it can be. According to the CDC, chronic pain affects around 20.4% of adults, 7.4% of whom have chronic pain that frequently limits their day-to-day activities [1].

How crazy is that? Millions of people with constant, long-term pain and no relief in sight.

Historically, the healthcare system has failed to address chronic pain adequately because it has primarily relied on pain killers as a solution to all types of pain. Consequently, this overprescription has led to an increase in addiction and overdose rates.

While the opioid epidemic is an issue in itself, Dr. Cristian Zanartu argues that the root cause is an “epidemic of pain”. There is misguided compassion directed towards a society in pain [2].

In essence, here’s how it goes: patients seek their doctors for pain relief. Doctors who haven’t been properly trained to address pain and suffering then turn to opioids. After all, prescribing Percocet is more straightforward than setting up cognitive behavioral therapy sessions. This cycle then perpetuates the reliance our society has on opioids.

But, what if there was another way to naturally relieve chronic pain… without pumping your system with drugs?

From a review of the available literature, we see that the results of using red light therapy for pain management are incredibly promising.

However, before we dive into them, let’s cover some background information about red light therapy and chronic pain.

What Is Red Light Therapy For Chronic Pain?

Red light therapy, also known as photobiomodulation and low-level laser therapy, involves shining red and near-infrared light in the 650-850nm spectrum. With its many benefits, medical professionals have long used red light therapy to treat various skin conditions, relieve pain, and more.

The first recorded use of red light therapy was in 1903 when Niels Finsen, a Faroese physician, used it to treat smallpox lesions. However, it wasn’t until the late 1900s and early 2000s that researchers began to study red light therapy’s effects on chronic pain.

More on these studies in a bit…

What Causes Chronic Pain?

People can develop chronic pain from a variety of sources.

It can come from a previous injury, such as an accident that left them with chronic neck pain or a sports injury that causes chronic knee pain.

Diseases such as arthritis, fibromyalgia, or shingles can also cause chronic pain. Unfortunately, even with treatment, these chronic conditions can continue to cause pain.

Beyond the physical, chronic pain can also impact your mental health, as it can cause anxiety, fear, and stress. These feelings are all interconnected, which can exacerbate the pain and cause it to worsen, resulting in a vicious cycle.

Does Red Light Therapy Work For Chronic Pain?

In short, yes. Red light therapy can work for chronic pain.

Several studies have shown red light therapy to effectively relieve certain types of chronic pain like back and arthritic pain. However, there’s not enough conclusive evidence to say that red light therapy can eliminate every type of chronic pain.

Read on below to see what types of chronic pain red light therapy works best for…

Red Light Therapy For Chronic Back Pain

In a seven-week study, researchers recruited patients who’d had chronic lower back pain for at least six years. They then split these patients into two groups: one received infrared light therapy, and one received a placebo. Both groups continued taking their medications as usual. 

After seven weeks, the patients who received red light therapy reported a 50% reduction in pain. The control group only reported a 15% reduction in pain [3].

Red Light Therapy For Arthritis

Red light therapy can help alleviate arthritis symptoms, such as joint pain, swelling, stiffness, and joint inflammation.

Because there are more than 100 types of arthritis, we’re only going to focus on the two most common ones for now: rheumatoid arthritis (RA) and osteoarthritis (OA).

Diagram comparing a healthy joint, a joint with rheumatoid arthritis, and a joint with osteoarthritis

Red Light Therapy For Rheumatoid Arthritis

Rheumatoid arthritis is an autoimmune disease where your body’s immune system attacks the lining of your joints – more specifically, the synovium.

Because the synovium is responsible for keeping your joints lubricated, any damage to it can result in pain and stiffness, especially as your inflamed synovium thickens.

Researchers conducted a meta-analysis of five placebo-controlled trials. These studies involved a total of 222 RA patients over seven years. Compared to the control group, they noted the following results:

  • Red light therapy reduced pain by 70%
  • Red light therapy reduced morning stiffness duration by 27.5 minutes
  • Red light therapy increased tip to palm flexibility by 1.3 cm

However, red light therapy did not seem to significantly improve range of motion or local swelling [4].

As a result, we see red light therapy as something that can supplement conventional RA treatments. It may be best for people who don’t get adequate pain relief from non-steroidal anti-inflammatory drugs (NSAIDs) like Advil.

Red Light Therapy For Osteoarthritis

Osteoarthritis is a chronic degenerative disease characterized by a breakdown of the cartilage that protects your joints. Usually, cartilage prevents the bones within your joint from rubbing together. However, with OA, the cartilage breaks down, and your bones start rubbing against each other, leading to intense pain and stiffness.

Fortunately, there are plenty of studies looking at red light therapy’s effects on knee, finger, wrist, neck, jaw, shoulder, and back pain when it comes to OA.

In one study, researchers randomly assigned 50 patients with degenerative OA of both knees into three groups. 15 patients received red light, 18 patients received near-infrared light, and 17 patients received a placebo.

Patient with knee joint pain seeing a doctor

Patients applied treatment to both sides of their knees for 15 minutes, twice a day for ten days. At the end of the ten days, researchers re-evaluated the patients’ pain and disability.

They found that patients who received red or near-infrared light had a 50% reduction in pain, per the McGill Pain Questionnaire, Present Pain Intensity, and Visual Analogue scale. The placebo group did not report any significant reductions in pain.

What makes this study even more interesting is that researchers also kept track of when these patients asked for re-treatment. This measure would tell researchers how long the effects of the above treatment procedure would last.

On average, patients who received red or near-infrared light requested re-treatment in 4.2 and 6.1 months, respectively. These numbers tell us that, while both red and near-infrared light work to relieve chronic knee pain, near-infrared light may be more effective. Patients who received the placebo, on the other hand, requested re-treatment within 0.53 months [5].

In another study, researchers asked 34 patients with Heberden’s and Bouchard’s OA to undergo red light therapy. Unlike the previously mentioned knee osteoarthritis study, there was no control group this time. Instead, researchers randomly assigned patients into groups that differed on the number of treatment sessions. 18 patients received five treatments, ten patients received seven treatments, and six patients received ten treatments.

Heberden’s and Bouchard’s OA refers to OA of the hand, where swelling occurs around the finger joints. This bony swelling can lead to pain, stiffness, and sometimes weakness.

Patients in all groups reported a significant reduction in pain and swelling. They also had an increased range of motion. However, researchers didn’t observe any additional changes between patients who received 7 and 10 treatments [6].

While more studies are needed to investigate the long-term effects, red light therapy can be an effective pain management solution for OA.

Red Light Therapy For Fibromyalgia

Fibromyalgia (FS) is a long-term, chronic issue that has symptoms of widespread muscle pain, fatigue, and sleep issues. Because medications can only offer partial relief from symptoms, many FS patients report significantly lower quality of life. What’s worse, only around 47% of FS patients take their medications as prescribed [7].

Fortunately, according to the latest research, red light therapy may be an effective alternative treatment to relieve fibromyalgia-associated pain.

In one study, researchers assigned 34 FS patients into control and treatment groups. They then looked at how red light therapy affected patient outcomes on a variety of assessments, from the number of tender points (NTP) to the Fibromyalgia Impact Questionnaire (FIQ) to the global improvement on a verbal scale (VSGI). These clinical evaluations were performed before, immediately after, and six months after the patients underwent red light therapy.

The results were fascinating.

Immediately after treatment, both groups reported improvements in NTP and morning stiffness. However, only the red light therapy group saw improvements in FIQ, VSGI, and total myalgia scores.

But, after six months, only the red light therapy group reported continued improvements in all the previous outcome measures [8].

These findings suggest that red light therapy can be an effective short and long-term treatment solution for reducing fibromyalgia pain in patients.

Red Light Therapy For Neuropathic Pain

Neuropathic pain (aka nerve pain) affects around 10% of Americans and is often described as a shooting, burning pain [9]. However, unlike “traditional” pain, neuropathic pain isn’t triggered by a specific event or injury.

For example, in phantom limb syndrome, the nerves may mistakenly send signals to the missing limb. The brain then interprets these impulses as pain messages.

A 2014 study looked at red light therapy’s effects on injured sciatic nerves in rats. The rats who received red or near-infrared light experienced significant pain relief, per improved paw withdrawal thresholds. Researchers concluded that the 660nm wavelength light (red) had more significant therapeutic benefits than the 980nm wavelength light (near-infrared) [10].

Paw withdrawal latencies (PWLs) are used to infer pain and hyperalgesia in animals. The longer it takes an animal to withdraw its paws from painful stimuli, the less sensitive the animal is to pain.

Red Light Therapy For Scar Pain

Red light therapy can help relieve scar pain by improving skin healing and softening the scar. While red light therapy may not eliminate scar pain immediately, it can help ease the pain over time and reduce the scar’s visibility.

A 2010 study investigated the effectiveness of red light therapy in the wound healing process. More specifically, researchers wanted to see if red light therapy could prevent or reduce the development of hypertrophic scars or keloids.

Patients with scarring from acne or surgery underwent scar revision surgery or CO2 laser ablation. After this procedure, researchers instructed patients to use red light therapy daily for 30 days.

Based on many assessments like the Vancouver Scar Scale (VSS), researchers concluded that red light therapy led to better outcomes than the control. What’s more, patients reported zero treatment-related side effects [11].

How Does It Work?

At its core, red light therapy works by stimulating our body’s cells to better repair and maintain themselves. More specifically, red light therapy enhances our mitochondrial functioning via greater adenosine triphosphate (aka energy) production. This cellular optimization then shows itself in a multitude of ways like:

  • Reduced Inflammation
  • Improved Blood Flow
  • Reduced Pain Sensitivity
  • Increased Opioid-Receptor Binding

You can read more about how red light therapy works here. Or, you can watch the video below for an explanation of the mechanisms behind red light therapy.

Reduced Inflammation

While inflammation is part of the healing process, chronic inflammation can prevent your body from healing correctly. In addition, persistent inflammation can worsen your chronic pain and even lead to other health complications.

Rheumatoid arthritis, for example, is very much connected to chronic inflammation – the more active your RA, the worse your inflammation. If left untreated, this inflammation can spread to other parts of your body, leading to irreversible joint damage. That’s why RA patients must manage their inflammation through lifestyle changes and medications.

Fortunately, red light therapy has been proven to reduce inflammation. More specifically, it reduces the levels of pro-inflammatory cytokines, which are responsible for stimulating the inflammatory response in your cells [12].

Typically, pro-inflammatory cytokines are “good” because they work with your immune system to fight off bacteria and viruses. However, they can sometimes be “bad” if they lead to unnecessary inflammation, like in RA.

Improved Blood Flow

Your blood is responsible for delivering oxygen, nutrients, and more to your body’s cells. Without these necessities, your body’s cells cannot function at their best, putting you at risk for other health conditions. Poor blood circulation can even lead to pain in your limbs if left untreated.

Red blood cells transporting oxygen and nutrients to cells

On the other hand, greater blood circulation can lead to increased healing and pain relief. These benefits occur because your cells now have the oxygen and nutrients they need to function correctly. As a result, you’ll experience faster cellular regrowth and regeneration, a combination of activities that works to reduce inflammation, improve tissue repair, and quicken muscle recovery.

What’s more, increased blood flow also means improved waste removal, as your body will be more efficient at removing cellular waste.

Researchers have found red light therapy to improve blood flow by 48%, from 7.47 ml/100 g/min to 11.08 ml/100 g/min, in a 2016 clinical study [13].

Now, you might be wondering: how exactly does red light increase blood circulation?

Clinical trials show that red light therapy increases nitric oxide (NO) production. Researchers took blood samples from patients before, during, and after red light therapy in the study. They found that red light therapy significantly increased NO levels in the blood [14].

Nitric oxide plays a vital role in blood vessel health. As a vasodilator, it relaxes the inner muscles of your blood vessels, leading to increased blood flow and lower blood pressure.

Reduced Pain Sensitivity

For something to be felt as “painful”, it needs to trigger our sensory nerve cells called nociceptors. These cells have a minimum threshold that must be met before sending a “pain” signal to our brains, aka our pain sensitivity.

Red light therapy has been shown to block fast axonal flow in rats, translating into needing more intense stimuli to trigger nociceptors [15].

In other words, red light therapy can reduce how much pain you feel by making you “less sensitive” to pain.

Increased Opioid-Receptor Binding

As you probably know, opioids provide pain relief by binding to opioid receptors in your central nervous system (CNS). While effective, opioids that act on these CNS opioid receptors can result in unintended side effects like sedation, tolerance, and dependence.

Red light therapy treatments, on the other hand, do not activate opioid receptors in your CNS. Instead, red light therapy works to activate opioid receptors in your peripheral nervous system (PNS).

More specifically, red light therapy can help send opioid-containing leukocytes to the damaged tissue [16].

We won’t be going too in-depth about how exactly this works, but here’s a great study you can check out if you want to learn more: https://pubmed.ncbi.nlm.nih.gov/18177605/

While not as effective as opioids, red light therapy can still significantly reduce pain levels without many of the side effects associated with opiate usage.

Your central nervous system includes your brain and spinal cord. Your peripheral nervous system includes everything else.

Final Thoughts

Numerous studies and clinical trials show that red light therapy can be an effective drug-free, pain-relieving treatment option that provides significant benefits for chronic pain sufferers.

With its anti-inflammatory and analgesic effects, red light therapy makes for an excellent alternative for people who want to avoid pain meds and their many side effects.

References

  1. https://www.cdc.gov/nchs/products/databriefs/db390.htm
  2. https://ascopubs.org/doi/full/10.1200/JOP.19.00285
  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2539004/
  4. https://pubmed.ncbi.nlm.nih.gov/16235295/
  5. https://pubmed.ncbi.nlm.nih.gov/1727843/
  6. https://pubmed.ncbi.nlm.nih.gov/26833862/
  7. https://journals.humankinetics.com/view/journals/ijatt/17/4/article-p28.xml
  8. https://content.iospress.com/articles/journal-of-back-and-musculoskeletal-rehabilitation/bmr00137
  9. https://www.sciencedirect.com/science/article/abs/pii/S0304395913006106
  10. https://link.springer.com/article/10.1007/s10103-014-1552-1
  11. https://onlinelibrary.wiley.com/doi/abs/10.1002/lsm.20952
  12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5523874/
  13. https://pubmed.ncbi.nlm.nih.gov/27416624/
  14. https://pubmed.ncbi.nlm.nih.gov/23334615/
  15. https://pubmed.ncbi.nlm.nih.gov/17374099/
  16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4137223/
Anne, Founder of Therapeutic Beams

Anne Linde

Since using it to clear up her acne in college, Anne has been an avid user and fan of all things light therapy. She now primarily uses red light therapy for its anti-aging benefits. Anne's mission is to make the science behind red light therapy easy to understand and accessible, so anyone can use it to take control of their health and wellbeing.

2 thoughts on “Red Light Therapy For Chronic Pain: The Science Behind Why It Works”

  1. Hi Anne,
    I am an esthetician specializing in noninvasive anti-aging. I have used light therapy for many years and truly see what it can accomplish as far as antiaging goes. Of course, I only use medica grade equipment.
    I am interested in offering pain Management treatments utilizing light therapy in my practice.
    Can you offer me any practical advice?

    thanks,
    Patricia

    Reply
    • Hi Patricia, thanks for reaching out! Because pain generally tends to be localized, I’d recommend a device that offers targeted treatment over something like a red light therapy bed. A handheld device, for instance, will give you more treatment flexibility and control than a panel, which may be ideal for treating something targeted like joint pain. You’ll also want to find a device that offers both red and near-infrared light. And, as someone that specializes in non-invasive anti-aging, you probably know how important it is to manage client expectations. While red light therapy has been shown to help relieve pain, it’s not something that typically happens overnight, and clients may need successive treatments to experience noticeable results – so communicating this to your clients is super important.

      Reply

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