Butterbur (Petasites hybridus) is native to Europe, northern Africa and southwestern Asia and has been used for centuries as an herbal treatment for headaches, back pain, asthma, and painful urinary spasms. Recent research suggests that it may be an effective treatment for hay fever and a means of preventing some migraines.
Results of a study indicating that butterbur works as well as a conventional treatment for hay fever were published in the British Medical Journal in January 2002. A team of Swiss researchers compared butterbur to the antihistamine cetirizine (Zyrtec) in a double blind trial that included 125 patients. While promising, these findings should be confirmed in larger studies that also look at butterbur's long-term effects. One very allergic patient seen in the Integrative Medicine Clinic (http://integrativemedicine.arizona.edu/) at the University of Arizona has reported dramatic improvement on butterbur. Otherwise, I have no experience with it, and usually recommend freeze-dried stinging nettle leaves for hay fever.
Butterbur has been available for migraine prevention in Europe and is gaining some recognition in the United States. Results of a small study published in the May 2000 issue of the journal Headache showed that an extract of butterbur root significantly reduced the frequency of migraine attacks and days per month of migraines with no adverse drug reactions from the butterbur extract or the placebo among the 58 patients participating. Studies have shown that adverse effects of using butterbur extract for migraine prevention are rare and tend to be mild gastrointestinal upsets. My colleague Tieraona Lowdog, MD, is enthusiastic about butterbur's efficacy in migraine prevention.
If you decide to try butterbur for migraines or hay fever, be very careful about the products you chose. The crude herb contains pyrrolizidine alkaloids (PAs) that are toxic to the liver. PA-free butterbur extracts are available; only use such products. Some butterbur extracts are standardized to contain a minimum of 7.5 mg of Petasin and Isopetasin. The adult dosage ranges from 50-100 mg twice daily with meals.
Andrew Weil, M.D.