Light and photobiomodulation
Red light (630–660 nm)
Red light in the 630–660 nanometre band is the visible part of photobiomodulation. It penetrates a few millimetres into skin and is absorbed by cytochrome c oxidase. It is the band the Red Light sauna takes its name from.
Also called red light therapy, 630 nm, 660 nm, visible red
Why this band. It sits inside the optical window where haemoglobin absorption has fallen away and water absorption has not yet risen, so light travels further into tissue than blue or green but remains visible and easy to specify. We name 630 nm for red light generally.
Depth. A few millimetres: red light reaches the epidermis and dermis. Near infrared reaches further.
The research. Our red light studies page collects the human research and links on to each source, and the sources carry the full citations. Read the findings as belonging to those studies and the devices they used.
Why it matters here
Red is the band the Red Light sauna takes its name from.