This article discusses general wellness practices involving red and near-infrared light. It is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease.

Red Light Therapy for Knee Pain: What the Research Shows and How to Use It

Updated October 2026

Knee pain is where the research on red light therapy is most encouraging, and also where it is easiest to oversell. This guide covers what the studies found, what the numbers mean in everyday terms, and how to use a home device sensibly.

Short answer: For knee osteoarthritis, pooled trials suggest red and near-infrared light can reduce pain modestly, especially alongside exercise. The effect is real in the data but not dramatic, results vary a lot between studies, and the best-studied doses came from clinical lasers rather than home panels. Used as a comfort tool next to strengthening and movement, it is a reasonable, low-risk option. It does not rebuild cartilage.

What the research shows

Researchers call this photobiomodulation (PBM) or low-level laser therapy. The knee is one of the better-studied joints.

  • Knee osteoarthritis, placebo-controlled trials. A 2019 meta-analysis of 22 randomized, placebo-controlled trials (1,063 participants analyzed) found pain was reduced by about 14 mm on a 100 mm scale compared with placebo at the end of treatment. In trials that followed World Association for Laser Therapy dose recommendations, the reduction was about 19 mm. The authors noted that results varied widely between trials (Stausholm et al., BMJ Open, 2019).
  • Older adults who exercise. A 2024 meta-analysis of 14 randomized trials found that adding photobiomodulation to exercise gave additional pain relief, better knee function and a small gain in range of motion. It found no clear difference in stiffness, walking tests or muscle strength (Li et al., Archives of Physical Medicine and Rehabilitation, 2024).
  • A counterpoint. At least one randomized trial found photobiomodulation added no incremental benefit for people with knee osteoarthritis already doing a strengthening program (Brazilian Journal of Physical Therapy, 2023).

Put together: there is a plausible, modest signal for knee pain, mixed evidence on whether it adds to exercise, and no evidence that it reverses joint damage.

The dose caveat for home devices

The trials above delivered measured energy to specific points on the joint line, usually with clinical lasers at 780 to 860 nm. A home panel spreads light over a much larger area, so you cannot copy a trial's numbers directly. What you can do is use a near-infrared device that delivers enough light to the knee at a known distance and follow its session guidelines. Our dosage and timing guide explains how distance and time interact.

How to use it at home

  1. Choose a device with 850 nm near-infrared, since near-infrared penetrates deeper than visible red.
  2. Position it at the distance recommended for your device, aimed at the front and sides of the knee.
  3. Keep the session length within the manufacturer's guidance. Start at the conservative end.
  4. Pair it with movement. The studies where light helped most paired it with exercise.
  5. Track pain and function for four to six weeks. If nothing improves, stop.

Stop and see a clinician if your knee is hot, visibly swollen, locks, gives way, or hurts after an injury.

Which device fits

  • Hooga Torch ($139): handheld with a precision tip, 120 mW/cm² by Hooga's specifications, for treating one knee at close range.
  • HG300 panel ($199): 660 nm red and 850 nm near-infrared, 73 mW/cm² at 6 inches by Hooga's specifications. It covers both knees and other areas.
  • PRO300 panel ($299): 109 mW/cm² at 6 inches by Hooga's specifications, for shorter sessions and more coverage.
  • Red Light Therapy Belt ($249): a wrap-style option you can position around the thigh or knee area while sitting.

Browse all options in the red light therapy collection. These are general wellness devices, not intended to diagnose, treat, cure or prevent any disease, including osteoarthritis.

Frequently asked questions

Can red light therapy regrow knee cartilage?

No human trial reviewed here shows that. The measured benefits are about pain and function, not structure.

How long until I notice a difference?

The reviewed trials ran a few weeks. Give a home routine at least four to six weeks before judging it.

Is it safe with a knee replacement or implants?

Ask your surgeon or physical therapist. Do not assume a home device is appropriate near implants or recent surgical sites.

Red light or near-infrared for knees?

The knee joint sits beneath muscle and tissue, so near-infrared (about 850 nm) is the wavelength most trials and devices use for joints. Many panels deliver both.

Back to blog