Most clinical studies have used 50–150 mg of butterbur extract daily in divided doses. For migraine prevention, dosages of 50–150 mg daily taken by mouth have been used. Note that if you use butterbur on a daily basis, it is important to monitor for signs of liver toxicity.^[1]

For allergic rhinitis, 50 mg of butterbur extract two to three times daily seems to have some benefit.^[2]