Natures Way Petadolex Pro-Active contains pure purple butterbur (Petasites hybridus) extract to support healthy blood vessel relaxation in the brain.* We use a patented extraction method to ensure that valuable petasites compounds are captured and that toxic levels of inherent compounds are left out. Our butterbur extract contains two compounds, petasin and isopetasin, which support healthy blood vessel tone.**This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.