Red light interacts with the body in a similar way to infrared light – This it thought to involve a few mechanisms including by increasing
energy (ATP) generation on the cellular level.
The key difference between red and infrared is that red wavelengths of light are absorbed and used in the first 25mm of skin tissue,
whereas infrared light can penetrate much deeper into the body.
This same mechanism is also responsible for many of the benefits of sunlight, which contains the red wavelengths as part of its spectrum.
LED light devices can reach through the entire skin layer, healing from the bottom up.