Close-up of a red light therapy device emitting infrared light for recovery and inflammation reduction

Red light therapy is often marketed as though a few minutes under a glowing panel can solve every painful knee from arthritis to a meniscus tear. It cannot. But photobiomodulation (PBM)—the clinical term for red and near-infrared light treatment—may be a useful, non-drug adjunct for some people with knee osteoarthritis and localized knee discomfort.

The important word is adjunct. Red light therapy does not diagnose the source of knee pain, rebuild worn cartilage on demand or replace strength work, activity modification, medical assessment or rehabilitation when those are needed. Used thoughtfully, it may be one tool that helps make a painful knee more manageable while the bigger plan addresses why it hurts in the first place.

Red Light Therapy for Knee Pain at a Glance

  • Best fit: It may be worth considering as an adjunct for some people with knee osteoarthritis or localized knee discomfort—not as a one-size-fits-all answer to knee pain.
  • What research suggests: Studies point to possible improvements in pain and function, but the evidence is mixed and does not support a guaranteed result, a universal dose or a fixed number of sessions.
  • What it cannot do: Red light therapy does not diagnose the source of knee pain, repair cartilage on demand or replace movement-based rehabilitation and medical care when those are needed.
  • How we use it: At Excelsior, RLT can be booked as a 10-minute standalone cycle for one area or as a 20-minute application after manual therapy within a Massage Therapy + Red Light Therapy appointment.

What Does the Research Say About Red Light Therapy for Knee Pain?

Most of the better research on photobiomodulation and knees concerns knee osteoarthritis. That distinction matters. A person may say “knee pain,” but the source could be osteoarthritis, patellofemoral pain, a tendon issue, a meniscus injury, referred hip pain, an acute sprain or something else entirely. Evidence for knee osteoarthritis should not be stretched into a promise for every sore knee.

A 2025 umbrella review of randomized-trial meta-analyses found that PBM was associated with improvements in knee-osteoarthritis pain and disability. The certainty was low for pain and moderate for disability; no outcome in the review reached high-certainty evidence. The authors also noted that the pain effect, although statistically significant, may have limited clinical impact when PBM is used by itself. That is a much more useful message than either “it does nothing” or “it definitely works.”

Read the 2025 umbrella review of photobiomodulation .

Older randomized studies are part of why PBM remains worth studying. One 1992 trial of 50 older adults with knee osteoarthritis found improved pain and disability outcomes after a short course of red or infrared light compared with placebo. It is an interesting signal, not a blank cheque: the participants self-applied treatment twice daily for 10 days, using equipment and a protocol that are not interchangeable with every modern panel, pad or clinic service.

See the randomized knee-osteoarthritis trial .

The sensible conclusion is that red light therapy may be worth considering for some people with knee osteoarthritis as part of a broader conservative-care plan. Results vary, and it should be evaluated by changes that matter to the person—stairs, walking tolerance, getting up from a chair or day-to-day pain—not by how impressive the device looks in a social-media reel.

Why Results Vary So Much

“Red light therapy” is an umbrella label rather than one identical treatment. Devices can differ in wavelength, output, treatment area, distance from the skin, contact with the body and session duration. Those details affect how much light reaches the target tissue.

Red wavelengths are often used for more superficial tissue, while near-infrared wavelengths may reach deeper tissue. For a knee, that distinction is relevant—but it does not mean that a person can choose one number from an online chart and create a proven treatment protocol at home. The research uses a wide range of devices and methods, which is one reason researchers have not agreed on a single ideal dose, schedule or placement plan.

The 2019 systematic review and meta-analysis that is often cited in this area found better outcomes in studies using particular low-level-laser parameters. It did not establish one universal “correct” protocol for every person with knee osteoarthritis. A later review likewise describes the wide variation in wavelength, dosage and session schedules across studies.

Read the reviews:

That is why we do not promise a universal number of sessions, a guaranteed outcome or a cookbook dose for every knee. Human bodies are already complicated enough without pretending they came with identical instruction manuals.

How Photobiomodulation May Support a Painful Knee

PBM is non-thermal: it is not simply heating the knee. Red and near-infrared light are absorbed by cells and appear to influence cellular signalling, including pathways involved in energy metabolism, inflammation and pain modulation. Proposed effects include changes in mitochondrial activity, local circulation and inflammatory signalling.

Those mechanisms help explain why PBM is being studied for pain and tissue recovery, but they do not prove that it repairs a particular structure inside a knee. A useful clinical goal is more modest: reducing symptoms enough that a person can move more comfortably, tolerate rehabilitation better or get through ordinary activities with less irritation.

Man seated on the edge of a massage table wearing a white red light therapy wrap on his knee in a bright massage therapy clinic, in Toronto.

What Red Light Therapy Can—and Cannot—Do for Knee Pain

For the right person, red light therapy may be a low-intensity addition to a plan that also includes movement, strengthening, load management, manual therapy or medical care. Some people notice a reduction in stiffness or soreness. Others notice little change. A trial should be judged by function as well as pain: Can you walk farther? Are stairs less aggravating? Can you get up from a chair more easily? Is recovery after activity more predictable?

Red light therapy is not a substitute for an assessment when there is an acute injury, a suspected structural problem or unexplained persistent pain. It does not replace a knee brace, imaging, medication, physiotherapy, injections or surgery when those are clinically indicated. It is one optional part of conservative care—not the lead actor in every knee story.

When Knee Pain Needs Medical Assessment First

Do not use an at-home device or an add-on treatment to delay assessment if you cannot bear weight, have severe pain even at rest, a visibly deformed knee, marked swelling, fever or redness around the joint, locking or buckling, or new calf swelling, numbness or colour change. Those symptoms warrant medical attention. MedlinePlus has a clear summary of knee-pain red flags here: When to contact a medical professional for knee pain.

If you are unsure whether a light-based treatment is appropriate for your medical history, medication use or a new diagnosis, check with the relevant medical professional before proceeding. Device instructions and individual circumstances matter.

How Red Light Therapy Fits Into Care at Excelsior Integrative

At Excelsior Integrative, red light therapy is used as a targeted supportive modality—not as a promise to cure knee osteoarthritis or “fix” an undiagnosed knee. We look at the history of the problem, the activities that aggravate it, the tissue and movement findings relevant to massage therapy, and whether another type of assessment should come first.

A standalone red light therapy appointment is a 10-minute cycle on one area. If more than one area needs attention, additional sessions can be added. For people who are also booking massage, our Massage Therapy + Red Light Therapy session includes 20 minutes of RLT applied to target areas after manual therapy. That may suit someone dealing with chronic muscle tension, sports recovery, ongoing pain or a soft-tissue injury alongside a knee concern.

The massage component can address the surrounding tissues and movement contributors that a light treatment alone cannot address. Depending on the person, that may include the quadriceps, hamstrings, calves, hip muscles or other tissues that are contributing to how the knee is being loaded. It is a more useful conversation than treating the knee as though it lives alone at the end of a leg with no neighbours.

When RLT is provided within a massage therapy appointment by an RMT, it is eligible for reimbursement under most massage therapy benefits. The clinic is located near Yonge & Eglinton, serving Davisville, Mount Pleasant, Eglinton West, Leaside, Lawrence Park and Forest Hill.

Frequently Asked Questions

No. Knee osteoarthritis involves changes throughout the joint, and red light therapy does not reverse those changes on demand. It may be used as a supportive option for symptom management alongside an appropriate care plan.

There is no evidence-based number that applies to every person or every device. Research usually involves repeated treatments rather than a single session, but outcomes depend on the cause of pain, the device, the treatment approach and what else is part of the plan. Progress should be judged by meaningful changes in pain and function.

No. For knee osteoarthritis and many other knee complaints, movement and strength work are often central to long-term management. Red light therapy may be an adjunct that helps a person tolerate those other parts of care more comfortably; it should not be positioned as a replacement.

Yes. Excelsior offers a standalone 10-minute red light therapy cycle for one area. For multiple areas, additional sessions can be added. RLT can also be included after manual therapy within a Massage Therapy + Red Light Therapy appointment.

When red light therapy is provided as part of an RMT massage therapy appointment, it is eligible for reimbursement under most massage therapy benefits. Coverage always depends on your individual plan.

Related Readings

A broad, evidence-aware look at red light therapy for pain, recovery and other commonly promoted uses. [Read]

Pain on the outside of the knee is not always arthritis. Our guide to IT Band Syndrome (Runner’s Knee) looks at common loading and tissue factors that can contribute to lateral knee symptoms. [Read]

Learn how red light therapy is integrated with hands-on massage care at Excelsior Integrative. [Read]

Red Light Therapy for Knee Pain: A Realistic Takeaway

Research suggests that photobiomodulation may help some people with knee osteoarthritis, particularly as an adjunct to a broader plan. The evidence is encouraging enough to take seriously, but not strong enough to promise a specific result, a particular timeline or a universal protocol.

If knee pain is persistent, worsening or affecting your daily life, start by understanding the likely source. If red light therapy is appropriate, use it as one part of a plan that keeps the goal practical: calmer symptoms, better tolerance for movement and a knee that interferes with less of your life.

To explore the service itself, visit our Red Light Therapy page  or book Massage Therapy + Red Light Therapy.

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