How long does the redness that appears after blue light therapy last?

How long the skin will be red after blue light therapy depends on how strong the treatment is and what skin type you have. But here is a general rule: Typical Redness DurationMild At-Home Treatment (LED masks, appareils portables): 0–2 hours (usually no lingering redness). Professional treatment (at a dermatologist or clinic): A few hours […]