Why the amount of light matters

How the study worked

The author reviewed cell, animal and some human research on red and near-infrared light and inflammation. This area is often called photobiomodulation.

The results

The review describes light absorption in mitochondria, particularly by cytochrome c oxidase, with possible roles for light-sensitive calcium channels. Proposed effects include changes in cell energy, nitric oxide and repair signals.

In stressed cells, studies often found less oxidative stress and fewer inflammatory markers. Small doses may stimulate activity while larger doses may slow it down.

What is still unclear

Much of the research was on cells or animals. Many studies concerned joints, the brain or lungs rather than facial skin.

What to take from this

More light is not always better. This review describes why a small dose and a large dose can have different effects.

Devices that list similar light

Four of the 5 masks in the comparison list a wavelength in every band used here (red, 620–670 nm and near-infrared, 800–870 nm). They are examples, listed alphabetically, each with our specification page and the manufacturer’s own product page. Related devices are examples, not evidence that a study tested that retail model.

• CurrentBody Skin LED Face Mask Series 3415 · 532 · 590 · 633 · 830 · 1072 nm · CurrentBody product page
• Dr. Renú SpectraLift Advanced465 · 530 · 630–660 · 850 nm · Dr. Renú product page
• Omnilux Contour Face633 · 830 nm · Omnilux product page
• Shark CryoGlow FW312415 · 630 · 830 nm · Shark product page

These masks list one of the bands, but not all:

• Dr. Dennis Gross DRx SpectraLite FaceWare Pro415 · 630; page also lists 605 · 880 (unresolved) nm · Dr. Dennis Gross product page

Matching a wavelength is not the same as matching the study. Dose, irradiance, session length and schedule also differ, and a mask’s reported output is not independently measured. See how dose works and home vs clinic doses.