Red light therapy is a complementary option that may provide modest, short-term relief from arthritis pain and stiffness, especially in knee osteoarthritis. A 2024 systematic review of 10 randomized placebo-controlled studies involving 542 people found less pain at rest than placebo, but the evidence was rated very low certainty.
Red light therapy is not a cure and should not replace exercise, appropriate medication or physical therapy.
For rheumatoid arthritis, the evidence is less certain. Red or near-infrared light therapy may ease some symptoms, but it does not replace disease-modifying antirheumatic drugs or care from a rheumatologist.
Red Light Therapy for Arthritis at a Glance
| Question | Evidence-based answer |
|---|---|
| Can it reduce arthritis pain? | Possibly, especially short-term pain from knee osteoarthritis |
| Can it reduce stiffness? | It may help, but results are inconsistent |
| Does it rebuild cartilage? | There is no reliable evidence that it reverses cartilage loss |
| Is it a cure for arthritis? | No |
| Is it useful for rheumatoid arthritis? | Evidence is mixed and insufficient |
| Should it replace medication? | No |
| Is it generally safe? | Usually low risk when used correctly, but precautions apply |
How Does Red Light Therapy Work for Arthritis?
Red light therapy, also called photobiomodulation, low-level light therapy or low-level laser therapy, uses low doses of red or near-infrared light directed at the treatment area. Unlike a heat lamp, photobiomodulation is designed to affect cellular activity without significantly heating the skin.
Researchers have proposed that photobiomodulation may affect inflammation, pain signaling and tissue metabolism. The results depend on factors such as wavelength, energy dose, power density, treatment distance and the number of sessions.
Devices sold as red light therapy products do not all deliver the same treatment. A result from one device cannot automatically be applied to another.
What Does the Research Show for Osteoarthritis?
For knee osteoarthritis, photobiomodulation may reduce pain for some people, but the expected benefit is modest and uncertain.
The 2024 systematic review and meta-analysis included 10 randomized placebo-controlled studies involving 542 people with knee osteoarthritis. Photobiomodulation reduced pain at rest compared with placebo and may have improved disability. Every included study was judged to have unclear or high risk of bias, and the certainty of evidence was very low. The researchers concluded that photobiomodulation may complement established treatments, but they could not confidently recommend using it on its own.
Earlier research was less positive. A 2015 meta-analysis found no convincing improvement in knee osteoarthritis pain, stiffness or function compared with sham treatment. The difference between these findings suggests that treatment settings and study quality may affect the results.
There is no reliable evidence that red light therapy repairs worn cartilage or stops osteoarthritis from progressing.
What About Rheumatoid Arthritis?
For rheumatoid arthritis, red light therapy may offer symptom relief, but the evidence is too uncertain to show that it works reliably.
Rheumatoid arthritis is an autoimmune disease, so reducing pain is not the same as controlling the disease itself.
A systematic review of 18 randomized trials involving 793 people found low-quality or very uncertain evidence for low-level laser therapy. Infrared laser may not be better than sham treatment for pain, stiffness, grip strength or function. Evidence for red laser was insufficient to support or reject its effectiveness.
Another meta-analysis found immediate improvements in pain and function after laser therapy, but no clear improvement in morning stiffness or pain three months later.
Red light therapy should only be used as an add-on for rheumatoid arthritis. It must not replace disease-modifying treatment such as methotrexate or biologic therapy when prescribed. The American College of Rheumatology guideline focuses on disease-modifying antirheumatic drugs and other medical treatment because controlling inflammation is essential.
Red Light Versus Infrared Light for Arthritis
Many arthritis devices use both visible red light and near-infrared light, but the terms describe different types of light:
- Red light is visible light commonly used in photobiomodulation and dermatology devices.
- Near-infrared light is invisible and may penetrate somewhat deeper into tissue.
- Infrared heat devices use light mainly to warm tissue and temporarily relieve stiffness or muscle discomfort.
- A device's clearance or registration applies only to its specific wavelength, intended use and claims.
For example, an FDA-cleared device document lists infrared light for topical heating related to arthritis, muscle spasm and stiffness. Its red-light setting is listed for facial wrinkles. That does not mean every red-light panel is cleared to treat arthritis.
Is an At-Home Red Light Device Worth Buying?
An at-home device may be reasonable if:
- You have a confirmed arthritis diagnosis.
- You expect possible symptom relief rather than a cure.
- The device provides its wavelength, irradiance, treatment time and intended use.
- You can accept a small or absent benefit.
- You continue your evidence-based arthritis treatment.
A large panel or higher power rating does not automatically mean better arthritis treatment. The FDA clears specific devices for specific uses, and "FDA approved" or "FDA certified" are not reliable descriptions for many consumer light products.
Clinical studies use different wavelengths, doses and treatment schedules. Results from supervised laser treatment therefore cannot automatically be applied to every consumer LED panel.
Safety and Who Should Avoid It
Low-level light therapy is usually low risk when used correctly, but light-based treatment can injure the eyes and may cause skin sensitivity, burns, itching, pigmentation changes or pain. Use the recommended eye protection and follow the manufacturer's exposure instructions.
The FDA advises against photobiomodulation procedures for people with:
- A photosensitivity disorder
- Medication that increases sensitivity to light
- An active implant such as a pacemaker or implantable cardioverter-defibrillator
- Skin cancer or a history of cancer at the treatment site
- An active infection, wound or lesion in the treatment area
- Pregnancy or plans to become pregnant
Speak with a healthcare professional before using a device if any of these apply to you.
Treatments With Stronger Support for Osteoarthritis
For knee, hip or hand osteoarthritis, red light therapy should generally follow treatments with stronger support, including:
- Strengthening and range-of-motion exercise
- Weight management when appropriate
- Physical therapy
- Topical nonsteroidal anti-inflammatory drugs for suitable knee or hand osteoarthritis
- Oral anti-inflammatory medication when medically appropriate
- Heat or cold therapy for temporary symptom relief
The American College of Rheumatology and Arthritis Foundation strongly recommend topical NSAIDs for knee osteoarthritis. They also strongly recommend exercise-based and other non-drug treatments as part of individualized care. Oral NSAIDs can help, but gastrointestinal, kidney, cardiovascular and medication-related risks need to be considered.
Bottom Line
Red light therapy is most reasonable as an optional add-on for arthritis symptoms, particularly knee osteoarthritis. The likely benefit is small, the evidence is low certainty and the treatment should not replace medication, exercise, physical therapy or rheumatoid arthritis care.
If you buy an at-home device, check its technical specifications and arthritis-related intended use. Protect your eyes, follow the exposure instructions and ask a clinician before use if you take photosensitizing medication or have an implant, cancer history or active skin problem.