The science of blue light therapy has been really well studied and documented.
Excess sebum production leads to the growth of the bacteria. The Propionibacterium acne bacteria feeds on sebum. It also causes oily skin, and plugs and enlarges pores.
Blue light LED or laser treat overactive sebaceous glands, and reduce the amount of sebum production. It also stimulates a molecule called Porphyrin, this is releases free radicals into the propionibacterium acne bacteria effectively killing it off. Treatment devices often a combine of both red, infrared and blue light.
Because the body’s immune system had stopped producing the antibodies needed to fight the acne bacteria; many people see an almost immediate reduction in inflammation after using blue light therapy.