Red-light therapy is all the rage — does it work?

This episode of the Nature Podcast explores the science behind red light therapy, a popular wellness trend marketed for everything from anti-aging to pain relief. Reporter Maren Hunsberger investigates the growing body of research supporting photobiomodulation—the use of specific red and near-infrared light wavelengths to stimulate cellular energy production via mitochondria. While some clinical applications, such as treating ulcers, nerve damage, and even neurodegenerative conditions like Parkinson’s and Alzheimer’s, show promise, the efficacy of at-home devices remains questionable. Experts like neuroscientist Juanita Anders and John Mitrofanes express skepticism about low-power consumer products, noting they often lack the intensity and proper wavelengths needed for real physiological effects. Despite this, both researchers use high-powered red light therapy themselves, highlighting a gap between commercial hype and scientific rigor. The episode also examines global obesity trends, revealing that while many high-income countries have seen obesity rates plateau or even decline—especially in France, Japan, and Spain—low- and middle-income nations continue to experience accelerating increases. The authors of a major Nature study suggest that access to healthy food, time, and socioeconomic resources play a key role in these disparities. While weight-loss drugs are transforming individual treatment, they haven’t yet significantly impacted population-level trends. The episode concludes with a call for more targeted, evidence-based public health interventions and rigorous clinical trials to separate science from pseudoscience in both fields.