Butterbur is most known for its use in migraine prevention, and several expert societies recommended it in the past but have since retracted their recommendation due to safety concerns.[1]
Butterbur has also been used for allergic rhinitis and asthma.[1] For intermittent allergic rhinitis, taking 50 mg of butterbur extract containing 8 mg of petasins 2–3 times daily for 2 weeks reduced symptoms of runny nose, sneezing, and itching compared to a placebo.[2] Small studies have suggested that it may be comparable to cetirizine or fexofenadine,[3][4] but larger studies are needed to be sure. Studies of butterbur in asthma have been too short and too low-quality to draw conclusions.[5][6]