European herbalists have been using Butterbur for decades and scientific studies have demonstrated that Petasins, the active constituents in Butterbur, can support healthy blood flow to the brain and promote normal neurological function. In this way, Butterbur, with synergistic Feverfew, a well-known headache remedy, may help to maintain head comfort in healthy individuals. NOW Butterbur is also free of undesirable Pyrrolizidine Alkaloids (PA's), so it can be used regularly. Our NOW natural and organic Supplements are an effective way to ensure you and your loved ones are getting essential vitamins, minerals and nutrients for daily optimal health. Since 1968, NOW has been making top quality products that are tested to the highest standards to empower people to lead healthier lives. Our promise - what is on the label, is precisely what is in the bottle.