“Red and blue light are the most commonly used LED lights for skin therapy,” says Dr. Sejal, a board-certified dermatologist based in New York City. “Yellow and green have not been as well studied but have also been used for skin treatments,” she explains, and adds that the combination of blue and red light used at the same time is a “specialized treatment known as photodynamic therapy,” or PDT.
Red LED light
This color has been shown to “stimulate collagen production, reduce inflammation, and increase blood circulation,” Dr. Shah says, “so it is primarily used for ‘fine lines and wrinkles’ and wound healing.” In terms of the former, because it boosts collagen, “red light is thought to ‘address’ fine lines and wrinkles,” Dr. Farber explains.
Because of its healing properties, it may also be used as an add-on after other in-office procedures, such as laser or microneedling, to reduce inflammation and recovery time, Shah says. According to aesthetician Joanna , this means she can perform “an intense peel on someone that can normally leave ‘their skin’ red for hours, but then use infrared afterward and they walk out not red at all.”
Red light therapy may also help ease inflammatory skin conditions like rosacea and psoriasis.
Blue LED light
“There is encouraging evidence that blue LED light can alter the microbiome of the skin to improve acne,” says Dr. Belkin. Specifically, studies have shown that with continued use, blue LED light can help kill acne-causing bacteria and also reduce oil production in the skin’s sebaceous glands.
The various light colors may work to differing degrees, says Bruce, a clinical professor of dermatology at the University of Pennsylvania. “Clinical studies ‘are’ relatively consistent in showing a reduction in acne bumps when ‘blue light’ is used regularly,” he says. What we know for now, according to Dr. Brod, is that blue light has a “mild benefit for certain types of acne.”
Yellow LED light
As noted, yellow (or amber) LED light hasn’t yet been as well-studied as the others, but Dr. Belkin says it “can help reduce redness and healing time.” According to Cleveland Clinic, it can penetrate the skin at a deeper depth than its counterparts, and research has demonstrated its efficacy as a supplemental treatment to red LED light in helping to fade fine lines.
Green LED light
“Green and red LED light therapy are ideal treatments for healing broken capillaries because they help reduce signs of skin aging and trigger new collagen growth beneath the skin surface,” Dr. Marmur says. Because of this collagen-boosting effect, Dr. Marmur says green LED light can also be used effectively for helping to even out skin texture and tone.