Red Light vs Near-Infrared Light: What's the Difference?
If you've started researching red light therapy, you've probably seen two terms come up repeatedly: red light and near-infrared light.
They're often used together in red light therapy devices, but they're not exactly the same thing.
The most obvious difference is that you can see red light, while near-infrared light is largely invisible to the human eye. But the differences go beyond what you can see.
Here's a simple breakdown.
What is red light?
Red light is part of the visible light spectrum.
In red light therapy devices, you'll commonly see wavelengths such as 630nm and 660nm. The "nm" stands for nanometres and refers to the wavelength of the light.
Because these wavelengths fall within the visible spectrum, the LEDs produce the familiar red glow you associate with red light therapy.
Red wavelengths are commonly incorporated into routines focused on the skin and more superficial areas of the body.
What is near-infrared light?
Near-infrared - often shortened to NIR - sits just beyond visible red light on the electromagnetic spectrum.
Common wavelengths used in red light therapy devices include 810nm, 830nm and 850nm.
Unlike red light, near-infrared light is largely invisible to the human eye.
This sometimes causes confusion for first-time panel users. When near-infrared is switched on by itself, some LEDs may appear dim or completely off even though they're operating normally.
Near-infrared wavelengths can also reach deeper into tissue than visible red wavelengths, which is why devices often combine the two rather than treating them as interchangeable.
What's the difference between red and near-infrared light?
The main differences come down to wavelength, visibility and depth of penetration.
Red light uses shorter wavelengths and is visible to the human eye.
Near-infrared light uses longer wavelengths, is largely invisible and can penetrate more deeply into tissue.
This doesn't necessarily mean one is "better" than the other.
They have different characteristics, which is why you'll often find both in the same red light therapy device.
Why do red light therapy panels use multiple wavelengths?
Rather than relying on a single wavelength, some panels combine several red and near-infrared wavelengths.
This provides a broader spectrum of light within the one device.
RENOVO panels use five wavelengths:
630nm - red light
660nm - red light
810nm - near-infrared light
830nm - near-infrared light
850nm - near-infrared light
This combination gives you both visible red and near-infrared light within the same panel.
Can you use red and near-infrared light at the same time?
That depends on the device.
Some red light therapy panels allow red and near-infrared wavelengths to operate simultaneously, while others provide independent controls so you can select different modes.
RENOVO panels allow you to use red light, near-infrared light, or both together, giving you flexibility depending on how you want to incorporate the panel into your routine.
Why can't I see the near-infrared LEDs?
This is completely normal.
Because near-infrared wavelengths sit beyond the visible spectrum, your eyes cannot see most of the light being emitted.
That means switching a panel to its NIR-only setting can make it look as though some of the LEDs aren't working.
One simple way to check is to view the panel through your phone camera. Depending on the phone and its camera filters, near-infrared LEDs may appear as faint white, pink or purple-toned lights on screen.
So an LED not appearing bright red does not necessarily mean it isn't operating.
Should you choose red light or near-infrared light?
You don't necessarily have to choose between them.
If you're comparing red light therapy devices, look at the actual wavelengths included and whether the device offers both red and near-infrared light.
It's also worth considering the panel as a whole - including its size, irradiance, coverage, controls and how you intend to use it.
If you're still deciding which type of device is right for you, our guide to how to choose a red light therapy panel explains the main specifications and features worth comparing.
Finding the right setup for your routine
Understanding wavelengths is useful, but they are only one part of choosing a device.
Panel size and coverage can make just as much difference to how practical a panel is for your everyday routine.
RENOVO offers four sizes, from the compact Parvus through to the full-body Magnus, all using the same five red and near-infrared wavelengths.
You can explore RENOVO's red light therapy panels to compare the full range.
The bottom line
Red light and near-infrared light are closely related, but they're not identical.
Red light is visible and uses shorter wavelengths, while near-infrared uses longer wavelengths that are largely invisible and can penetrate more deeply.
Rather than thinking of one as better than the other, it makes more sense to understand what each contributes.
That's why many red light therapy devices - including RENOVO panels - combine both within a single system.