Red light therapy irradiance explained

Irradiance describes power delivered over an area and is commonly expressed in mW/cm². It is useful, but it should not be treated as a score where the largest number automatically wins.

Distance matters

Irradiance at the treatment surface can change with distance and measurement method. That means two numbers are only useful for comparison when you understand how they were measured.

Dose adds time

Delivered energy depends on more than instantaneous power. Treatment duration is part of the equation. This is why a device discussion should connect irradiance with dose and the protocol used in relevant research.