Red Light (around 633 nm)
Quick definition
Red light is the main anti-ageing wavelength used in LED beauty devices.
The Science
Red light is the visible wavelength most often used in face masks aimed at collagen support, overall skin tone, and fine-line reduction.
Why it matters for your skin
If an LED face mask does not clearly tell you its red wavelength range, it is harder to judge whether it is built around clinically useful specs.