What Is Red Light Therapy? (Photobiomodulation Explained)

Short answer: Red light therapy, also called photobiomodulation, exposes the skin to low-level red and near-infrared light from LEDs. Home devices range from handheld units and pads to full-body beds. Research is stronger for some uses than others, and results depend on the wavelength, power and dose a device delivers.

Last reviewed: September 2026. Educational only, not medical advice. See our disclaimer.

How it works, in general terms

Photobiomodulation means using light to influence how cells behave. Light at certain red and near-infrared wavelengths is absorbed by structures in cells, and researchers study whether that changes cellular activity. Studies have examined it for many purposes with varying results, and consumer devices differ widely in power. That is why the specs matter more than the marketing.

What is in a device

• LEDs. Light-emitting diodes at chosen wavelengths.
• Wavelengths. Red is roughly 620 to 700 nm and near-infrared roughly 700 to 1,100 nm. The most common pairing is about 660 and 850 nm.
• Irradiance. Measured in mW/cm², this is the power reaching your skin.
• Controls. Timers, presets and sometimes pulsing.

Device types

• Handhelds and small panels for small areas.
• Pads and belts for one area, hands-free.
• Helmets and head devices for the head.
• Full-body beds and systems for the whole body.

See everything we carry in Every Red Light Therapy Device We Carry, and start choosing with the buyer's guide.

What it is not

• It is not the same as an infrared sauna. See red light vs. infrared sauna.
• It is not a substitute for medical care.
• It is not a sunlamp or tanning bed.

Safety basics

• Use eye protection and follow the manufacturer's instructions.
• Check with a doctor if you have a medical condition, are pregnant or are photosensitive.
• Read red light therapy safety.

Read the Red Light Therapy Guide or ask our team.