What wavelengths should a red light therapy panel have?
If you are comparing red light therapy panels, one of the first specs you will see is wavelength.
Most panels list 660nm for red light and 850nm for near infrared light. Others mention 630nm, 660nm, 830nm, and 850nm. Some might not even mention wavelengths at all.
That combination is common because it gives you one visible red wavelength and one near-infrared wavelength in the same device. Red light is often used in skin appearance routines, while near-infrared is commonly used in body-focused wellness and post-exercise routines.
What does “nm” mean?
“nm” stands for nanometres.
It is a measurement of wavelength, which tells you what type of light the device emits.
In red light therapy, the most common wavelength ranges are:
|
Type of light |
Common range |
Common panel wavelengths |
|---|---|---|
|
Red light |
Around 600–700nm |
630nm, 633nm, 660nm |
|
Near-infrared light |
Around 780–1100nm |
810nm, 830nm, 850nm |
A review by de Freitas and Hamblin describes low-level light therapy as generally using light in the red and near-infrared regions, usually around 600–700nm and 780–1100nm. You can read the review here: Proposed mechanisms of photobiomodulation or low-level light therapy.
That does not mean every wavelength in that range is equally useful. It simply shows why red and near-infrared wavelengths are the main focus in most red light therapy panels.
Why 660nm is common
660nm is one of the most common red light wavelengths used in consumer panels.
It is visible red light, so you can clearly see it when the panel is switched on.
660nm wavelengths are usually marketed for:
- skin appearance routines
- face and neck use
- general red light exposure
- surface-level wellness routines
A skin-focused clinical study by Wunsch and Matuschka looked at red and near-infrared light treatment in 136 volunteers. The study used wavelength ranges that included red light between 611–650nm and a broader range up to 850nm. After 30 sessions, the treatment groups showed improvements in measures such as skin feeling, skin roughness, complexion, and collagen density compared with controls. You can read the study here: A controlled trial of red and near-infrared light treatment.
The limitation is important: that study did not test every home panel on the market. It used specific devices, session schedules, and measurement methods. So it supports the idea that red and near-infrared light can be relevant for skin appearance, but it does not prove that every 660nm panel will give the same result.
Why 850nm is common
850nm is a near-infrared wavelength.
Unlike 660nm, you usually cannot see 850nm clearly with your eyes. On many panels, the 850nm LEDs may look very dim or almost off even when they are working.
That is normal.
Near-infrared light is commonly included in panels because it is discussed for deeper penetration than visible red light. This is why many red light therapy panels combine 660nm and 850nm.
For home use, 850nm is usually marketed for:
- body-focused routines
- post-exercise recovery routines
- larger muscle area routines
- general wellness sessions
A review on the anti-inflammatory effects of photobiomodulation notes that many wavelengths in the red range of 600–700nm and near-infrared range of 770–1200nm have shown positive results in studies, while also pointing out that wavelength choice is only one part of the full picture. You can read it here: Mechanisms and applications of the anti-inflammatory effects of photobiomodulation.
I would not translate that into a strong medical claim. The practical takeaway is simply that 850nm is a widely used near-infrared wavelength and makes sense in a red/NIR panel.
What about 630nm and 830nm?
Some panels include additional wavelengths, often something like 630nm/660nm and 830nm/850nm.
Astudy on facial wrinkles used a combination of 633nm red light and 830nm near-infrared light in 31 subjects. Participants received nine treatments, and the researchers reported improvements in the skin surface, with assessments done using profilometry, photography, and satisfaction scores. You can read the PubMed summary here: Combination 633nm and 830nm LED light therapy study.
Again, the limitation is that this was a specific clinical protocol, not a test of every consumer panel. But it helps explain why 630–633nm and 830nm are often mentioned in the light therapy world.
Disclaimer
This article is for general educational purposes only and is not medical advice. Red light therapy products are intended for general wellness and lifestyle use unless specifically cleared for a particular medical purpose. Always follow your device instructions and consult a qualified healthcare professional if you have a medical condition, take photosensitising medication, have an eye condition, are pregnant, or are unsure whether red light therapy is suitable for you.