How Do Red Light Devices Work?

By Gerda Endemann, PhD

Usually if it sounds too good to be true, it isn’t true. So we were skeptical about the wellness and beauty benefits claimed for light, and for red light in particular. But the evidence is mounting that red light is a simple, noninvasive way to stimulate the health and rejuvenation of cells and tissues. And blue light can also be useful.

First, a quick summary of how the different wavelengths of light affect us: The color of light, and whether we can see it, is determined by its wavelength. The shortest wavelength our eyes can see is violet light, and the longest wavelength we can see is red light. In between come blue, green, yellow, and orange light. We don’t see
ultraviolet light (with wavelengths that are shorter than violet light) or infrared light
(with wavelengths that are longer than red light).

We know a fair bit about how the UV and infrared wavelengths that we can’t see affect our bodies. Infrared light is warming, and we love devices with infared  UV light is used by our skin to produce vitamin D, which is essential for cellular health, immunity, and bones. Of course, excessive UV light burns and damages skin, so doctors recommend using sunscreen and taking a vitamin D supplement as needed.

But it’s also turning out that visible red and blue wavelengths of light do more than just look pretty.


Clinical research has shown that red light triggers reactions in cells that support skin rejuvenation and boost smoothness, elasticity, and appearance. This is called photorejuvenation. One of the ways that red light appears to work is by supporting the production of collagen and reducing the amount of an enzyme (MMP-1) that breaks down collagen.

Red light can also promote the health of cells and tissues in other ways, including stimulating tissue maintenance and repair, and energy (ATP) production in cells’ power plants, the mitochondria.


    Strap on this soft, flexible, ultramodern mask for a 20-minute red light treatment at home instead of in your dermatologist’s office. LEDs in the Red Light Face Mask deliver both red light (630 nanometers) and near-infrared light (880 nanometers) wavelengths without any ultraviolet light. With regular use, the combination of red light and near-infrared light has been shown to promote the appearance of rejuvenated and smoother-looking skin.