This article explains why LED mask irradiance claims vary across brands and how to compare them fairly. It covers measurement distance, sensor type, wavelength breakdown, mask architecture, pulsing, dose calculation, safety standards, and red flags that reveal whether a product's mW/cm² spec is real data or marketing.

At-home light therapy treats acne using blue light (~415 nm) to kill C. acnes bacteria and red light (630–660 nm) to reduce inflammation. Devices come as masks, handhelds, and panels — choose by acne location and routine. Verify certification and irradiance, and expect results over 8–12 consistent weeks.