Red light therapy, clinically known as photobiomodulation (PBM), is gaining traction in longevity, recovery, and aesthetic medicine — but does it actually work? This evidence-based review examines how specific wavelengths of red (630–670 nm) and near infrared light (810–850 nm) interact with mitochondria to influence ATP production, inflammation, collagen synthesis, muscle recovery, and brain health. We break down the science behind cytochrome c oxidase activation, nitric oxi