BLUE WOMAN GROUP

Before anyone knew better, sunlight was prescribed as an acne treatment. The reason: blue light, a P. acnes- destroying wavelength within the visible light spectrum. “It essentially causes the bacteria to self-destruct,” says Dr. Zakia Rahman, clinical associate professor of dermatology at Stanford University. “When you go outside, however, you are getting visible light, but you are also getting ultraviolet light, which can cause damage that is precancerous.” (Needless to say, this is no longer a recommendation.) Targeted blue-light devices, like the Tria Positively Clear Acne Clearing Blue Light ($220), provide the same bacteria-eradicating benefits without exposing skin to any damaging UV rays. And while some derms offer professional blue-light treatments, it just isn’t as effective as doing it yourself, says Rahman. “P. acnes bacteria double every five hours; you’re not going to drive to my office every day for a treatment,” she says. “So, in this case, having the device to treat at home is actually more beneficial.” Cue up the Netflix and call it a night.