Both Petadolex Patented Brain Support  and Petadolex ASAP  contain a patented, standardized, and clinically studied extract of butterbur (Petasites hybridus). These herbal products feature a unique extraction method (for which the patent was granted) guaranteeing that they are free of pyrrolizidine alkaloids. Petasites hybridus has an approved monograph in the Complete German Commission E Monographs.