Red light therapy is a complementary option that may reduce inflammation in some localized muscle, joint, skin and wound-related conditions. The evidence is mixed and depends on the condition, device and treatment schedule. A 2023 review of 11 randomized controlled trials and a 2025 umbrella review reached cautious conclusions, with stronger support for pain, function and recovery in some conditions than for generalized inflammation.
Red light therapy is also called photobiomodulation, low-level light therapy or low-level laser therapy. It uses red and near-infrared wavelengths to affect cellular activity.
Red Light Therapy and Inflammation: At a Glance
| Question | Evidence-based answer |
|---|---|
| Can it reduce inflammation? | Possibly, especially in localized tissues and some injury-related conditions |
| Is it a proven treatment for all inflammation? | No |
| Is the evidence stronger for pain than inflammation? | Generally, yes |
| Can it replace anti-inflammatory medication or medical care? | No |
| Are home devices equivalent to clinical treatment? | Not necessarily; devices vary widely |
| Is it generally safe short term? | Usually, when used as directed |
How Might Red Light Therapy Reduce Inflammation?
Red and near-infrared light may affect mitochondria, cellular energy production, calcium signaling, nitric oxide and reactive oxygen species. These changes can affect inflammatory pathways and tissue repair.
Laboratory and animal studies suggest that photobiomodulation may reduce inflammatory signaling involving substances such as tumor necrosis factor-alpha, interleukin-1 beta and interleukin-6. Changes in inflammatory markers do not automatically show that a person will experience a meaningful clinical benefit.
The response may also depend on the dose. Photobiomodulation can have a biphasic response, meaning that too little light may have little effect, while excessive exposure may reduce or reverse the intended response. Treatment time, wavelength, power and distance from the device all matter.
What Does the Human Research Show?
Human research is promising but not conclusive.
The 2023 review found that some of the 11 randomized controlled trials reported improvements in inflammation, while another found no improvement. The review concluded that photobiomodulation may help with chronic pain and inflammation, but high-quality human research remains limited.
A 2025 umbrella review evaluated 15 meta-analyzes involving more than 200 randomized trials and over 9,000 participants. It found moderate-certainty evidence for some outcomes, including disability related to knee osteoarthritis. Most outcomes had low or very low certainty because of differences between studies, small sample sizes and possible publication bias.
The evidence therefore supports red light therapy more clearly for pain, function and recovery in certain conditions than for generalized inflammation throughout the body.
When Might Red Light Therapy Be Useful?
Red light therapy may be reasonable as an add-on treatment for:
- Localized muscle soreness or soft-tissue injury
- Some joint-related pain and stiffness
- Knee osteoarthritis rehabilitation
- Certain wound-healing applications
- Some inflammatory skin concerns, under dermatological guidance
The strongest practical case is usually localized inflammation linked to a diagnosed musculoskeletal or skin condition. Red light therapy is less established for systemic inflammation caused by autoimmune disease, infection, obesity or another underlying medical condition.
For example, evidence that photobiomodulation improves disability from knee osteoarthritis does not prove that it treats the underlying arthritis or removes joint inflammation. It may improve symptoms and function without addressing the cause of the disease.
Are Home Red Light Therapy Devices Effective?
Home devices may help, but their results are difficult to predict. Devices differ in:
- Wavelength
- Light intensity
- Treatment area
- Distance from the skin
- Session duration
- Total energy delivered
- Whether they use red light, near-infrared light or both
The American Academy of Dermatology notes that studies use different devices and treatment schedules, which makes results difficult to compare. Dermatology clinics also commonly use more powerful equipment than consumer devices.
An FDA-cleared device is considered low risk for its intended use, but FDA clearance does not prove that the device will effectively treat inflammation. The terms "FDA approved" and "FDA certified" can also be misleading because the FDA generally clears these devices rather than approving them as proven treatments.
If you use a home device, follow the manufacturer's instructions. Longer or more frequent sessions are not necessarily better.
Is Red Light Therapy Safe?
Short-term use appears to be generally well tolerated. Reported side effects include temporary skin irritation and mild discomfort. Long-term safety data for many consumer devices remain limited.
Speak with a healthcare professional before using red light therapy if you:
- Take medication that increases sensitivity to light
- Have lupus or another light-sensitive condition
- Have darker skin and are treating the face, because visible light may increase the risk of hyperpigmentation
- Have an eye condition or the device instructions require eye protection
- Are considering red light therapy instead of treatment for unexplained swelling, pain or inflammation
Use protective eyewear whenever the device instructions recommend it. Red light therapy should not delay assessment of symptoms that could indicate an infection, significant injury or inflammatory disease.
Bottom Line
If you are considering red light therapy, base the decision on the condition being treated, the device's specifications and the available medical guidance. It may support pain relief, function or recovery in some localized conditions, but it is not a general treatment for unexplained or body-wide inflammation.
Red light therapy should remain an adjunct to diagnosis and appropriate care, not a substitute for prescribed medication, physical rehabilitation or treatment of the underlying cause.