Why all Red Light Devices are Not The Same: Red Light Strength aka Irradiance

The power of a red light plays a major role the amount of effectiveness it will have. The bulb strength at any distance is called irradiance. It is usually expressed in milliwatts per square centimeter (mW/cm²). One technical dosing guide that compiles hundreds of photobiomodulation studies notes that surface treatments for skin often fall in the neighborhood of 10–200 mW/cm². Those below 50mW/cm can affect skin and collagen density but may not be powerful enough to produce other desirable red light benefits such as muscle recovery, deep tissue regeneration and scar and wound healing. Somewhere above 100 mW/cm is the sweet spot for reaping all the possible benefits but not feeling  any adverse affects. 

Higher strength is better up to this sweet spot, but higher after that point is not necessarily better. Studies have shown that irritation and redness can occur above 300mW/cm with no additional benefit. In extreme cases blistering can occur at 320mW/cm in colored skin and at 480mW/cm in caucasian and non-hispanic skin. A device that delivers below 300mw/cm will ensure no adverse effects occur from too much irradiance. 

Distance is part of the irradiance equation. For example a specific red light panel device measured its irradiation levels at 1100 mW/cm² right at the surface, about 180 mW/cm² at around 4 inches away, and about 40 mW/cm² at roughly 10–12 inches. In this case, if someone wanted all the red light benefits, they would need to stand very close but not touching this particular panel. If they were only wanting skin and collagen benefits, the standard panel 10-12 inch recommendation would be sufficient.  

However, that measurement of 1100 at surface and 40 at 6" may be inflated as many of the popular red light devices advertise their irradiance levels based on a solar meter measurement. Solar meters are made to measure full spectrum light and over-inflate readings of single or double wave-length red light. For similar red-light devices, when measured at 6" the actual spectrometer reading was 9mW/cm rather than the advertised 40mW/cm.

The Cocoon irradiance of 130mW/cm is right in the sweet spot of therapeutic benefits, was measured properly with a spectrometer rather than being overinflated and is designed  to be used while lying on and wrapped within The Cocoon right at the therapeutic surface or within a very small distance from the surface ensuring that the irradiance is not significantly affected by distance from therapeutic surface.