Phototherapy is supported by substantial evidence for improving skin quality and reducing symptoms of conditions like acne and psoriasis.

“the uses of the phototherapy for treatment of skin conditions and improving the quality of skin are wonderful and point to the fact that phototherapy can indeed improve the appearance of skin in conditions like acne can accelerate wound healing can improve the youthfulness appearance of skin but these effects tend to be somewhat mild to moderate when they occur”

“why this would be the case isn't exactly clear but there are number of different logical interpretations such as reduced inflammation improved mitochondrial function all Downstream of reduced reactive oxygen species improved blood flow to that particular area because of the effect that long wavelength light can have on vasod dilation of expansion as opposed to contraction of blood vessels and capillaries”