Man using a red light therapy wrap around his knee at home

Red Light Therapy for Pain: What the Evidence Says and What to Expect

Short answer: red light therapy, also called low-level light therapy or photobiomodulation, uses red (around 630 to 660 nm) and near-infrared (around 810 to 850 nm) light at low power. Cleveland Clinic describes it as a promising but still emerging treatment: there is some evidence for short-term relief of pain and stiffness in conditions such as osteoarthritis, tendon problems and muscle soreness, but studies are often small, use different doses and devices, and more research is needed. It appears safe when used as directed. A sensible expectation is modest, temporary relief for some people, used alongside proven measures such as exercise, not a cure for arthritis or any disease.

How is red light therapy supposed to work?

Unlike a heat lamp, the aim is not to warm the tissue. Red and near-infrared light penetrates the skin, near-infrared more deeply, and is absorbed by the energy-producing parts of cells (mitochondria). Laboratory studies suggest this can increase cellular energy production, improve local blood flow and reduce certain inflammatory signals. How consistently that translates into less pain in real life is what researchers are still working out.

What does the evidence show for pain?

  • Knee osteoarthritis and joint pain. Some trials and reviews report short-term reductions in pain and stiffness, particularly with near-infrared wavelengths at adequate doses. Others find little difference from sham treatment.
  • Tendon pain such as Achilles or elbow tendinopathy. Mixed results, with the better outcomes when light is combined with an exercise programme.
  • Muscle soreness and recovery. Several studies in athletes suggest reduced soreness after hard exercise.
  • Neck and low back pain. Some positive short-term findings. Quality of evidence is low to moderate.

Big claims you may see online, such as weight loss, reversing arthritis or treating serious diseases, are not supported by good evidence.

What types of device are there?

  • Flexible wraps and belts with built-in LEDs that fasten around a knee, shoulder, elbow or the lower back. Practical for joints because the light sits close to the skin.
  • Panels that treat a larger area from a short distance.
  • Combination devices such as knee or shoulder massagers that add heat, vibration or air compression. With these, much of what you feel comes from the heat and massage, which have their own benefits.

See our infrared therapy belt and the joint comfort and mobility collection.

How do I use red light therapy at home?

  • Follow the manufacturer's instructions for distance and time. Typical sessions are 10 to 20 minutes per area, three to five times a week.
  • Apply to clean, bare skin. Light does not pass through clothing.
  • Be consistent for four to six weeks before judging the result. If there is no benefit by then, it is probably not for you.
  • More is not better. Studies suggest there is a useful dose range, and longer sessions do not add benefit.
  • Do not look directly into bright LEDs. Use the eye protection provided with panels.

Is red light therapy safe?

It is generally considered safe and non-invasive when used as directed, with no UV exposure. Ask your doctor first if you are pregnant, have a history of skin cancer or suspicious lesions in the area, have a light-sensitive condition such as lupus, or take medications that increase light sensitivity (some antibiotics, acne medicines and diuretics). Do not use it over an area with active cancer. Stop if you notice skin redness, irritation or headaches.

What should I do alongside it?

The treatments with the strongest evidence for joint and tendon pain are still exercise, strengthening and weight management, supported by heat, cold and bracing where appropriate. See heat or ice for pain, knee pain going up stairs and Do knee compression sleeves work?

When should I see a doctor?

See a doctor for any joint that is hot, red and swollen, for pain after an injury, for pain that wakes you at night, or for pain that has not improved after a few weeks. Do not use any home device as a substitute for diagnosis.

Key takeaways

  • Red and near-infrared light therapy is promising for short-term pain relief, but the evidence is still developing.
  • Expect modest, temporary relief at best, and not for everyone.
  • Use on bare skin, 10 to 20 minutes, several times a week, for four to six weeks before judging.
  • Generally safe. Check first if pregnant, light-sensitive or with a history of skin cancer.
  • Keep doing what is proven: movement, strengthening and weight management.

Sources

This article is general wellness information and is not medical advice. Products mentioned are not intended to diagnose, treat, cure or prevent any disease. Please consult a qualified healthcare professional about your condition.

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