Why Red and NIR?

Light is an electromagnetic wave. The wavelengths determine the 'color' the human eye can see. The visible light spectrum, which is a fraction of the global radiation spectrum, is measured in nanometers. A nanometer (nm), one-billionth of a full meter, refers to the distance a light can travel before dispersing. Visible light wavelengths go from around 400nm to slightly over 700nm with ultraviolet light on one end and infrared light on another. There are also wavelengths outside of the visible spectrum. These are infrared, radio waves, x-rays, gamma rays, etc. Infrared means beyond red (it begins just after the red spectrum ends), and it’s wavelengths are too long for the eye to see.
  Near-Infrared (NIR) is closest to the red end of the visible light spectrum. While UV, green, yellow and blue wavelengths of light do penetrate the skin, none are able to match the penetrating power of Red and NIR light nor the benefits that come with it.
  Red and Near-Infared light are able to more deeply penetrate into tissues, vessels, nerves and even brain and bones. In addition, a combination of these two wavelengths have an important and specific impact at the cellular level. Red Light Therapy combines these two lights for a reason.
 

Red light wavelengths fall into the visible part of the light spectrum between 600-700nm. NIR light is right next to red, between 700-1200nm, has a longer wavelength and is invisible. The longer the wavelength the deeper the penetration to deliver energy to the cells. While red light treats the surface of the skin, NIR light goes much deeper stimulating healing and relieving pain.

An average human body contains approximately 50 trillion cells with about 200 different types (and within these cells there are about 20 different types of structures or organelles). Each type of cells has its own specific light absorption method. This means certain tissues consume certain kinds of light at optimal wavelengths only. So it turns out that it’s not enough for the wavelengths to be within Red and Infra Red spectrum: scientific research indicates that only one narrow band of light between 600nm and 950nm has been shown to activate cellular regeneration & anti-aging systems and only this light can be called light therapy.

But that's not all! Now we have to pick the most perfect wavelengths within the most perfect band of light. Studies have demonstrated that the red light in the visible spectrum at 660nm, and the invisible one at 850nm, are those most absorbed by the Cytochrome C Oxidase, enabling photobiomodulation to occur in the best possible way. “Two wavelengths of red light in particular—660nm and 850nm—deliver the best biological response, explains Michael Hamblin, M.D., an associate professor at Harvard Medical School. The former, 660nm, is more quickly absorbed by the skin, making it the go-to for cosmetic treatments, while 850nm penetrate deeper into your body to help with muscle recovery, joint pain, and full body health." Done.

 Our light wavelengths: 660nm (RED) + 850nm (NIR).

 
 
 
 
Links to more information about Red and NIR:

https://www.researchgate.net/publication/265212409
https://www.researchgate.net/publication/23797391
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4745411/
https://www.dovepress.com/articles.php?article_id=23271    
 
Links to studies: here