Enzymatic Therapy, Petadolex, Pro-Active, 60 SoftgelsThe Safe, Pure Butterbur Relaxes Blood Vessels in the Head Dietary Supplement Enzymatic Therapys Petadolex Pro Active supplement contains pure butterbur extract to support healthy blood vessel tone in the head, as well as normal blood flow in the brain. The patented method of extraction for Petadolex Pro Active ensures the valuable petasites compounds are captured, while leaving out toxic levels of inherent compounds such as pyrrolizidine alkaloids.