The surprising science behind red-light therapy — and how it really works

Nature sought the expertise of Praveen Arany in an article about the science behind red light therapy. Experts say a pattern might be emerging, that when cells are healthy, external light often has little effect. But during illness or metabolic stress, in which mitochondrial dysfunction is common, its impact seems to be stronger. That distinction could help to explain why results vary across studies. But mitochondria probably do not tell the whole story. “Even if you use a mitochondrial inhibitor, we still see a therapeutic response,” Arany said.