Reviewed by: HU Medical Review Board | Last reviewed: May 2023

Butterbur comes from the butterbur plant (Petasites hybridus), which is a perennial shrub found in Europe, Asia and parts of North America. It grows in wet, marshy soil, damp forests and along rivers and streams. Butterbur has long been used as an herbal treatment for migraines, headaches, asthma, urinary tract infections, wounds, allergies, and stomach upset. Butterbur products may be made from the plant's root, stem, or leaves.1

How butterbur works

The substances petasin and isopetasin are found in butterbur. While the exact way these compounds work isn't fully understood, it is believed that they work to reduce inflammation. These actions are thought to help prevent migraine and reduce migraine headaches.2

Scientific studies on butterbur and migraine

The effectiveness of butterbur in migraine prevention has been evaluated in several research studies. Several trials have compared butterbur to placebo and found that butterbur, specifically the formulation Petadolex®, was significantly more effective in reducing the number of migraines in a month.2,3

Formulations available

Butterbur is sold in a variety of formulations, including capsules, powders, tinctures, and teas. Some of the chemicals in butterbur, called pyrrolizidine alkaloids (PAs), are known to cause liver damage, and only those products labeled or certified as PA-free should be used.1

Side effects and other precautions

Known side effects from butterbur include:

  • Burping or belching
  • Headaches
  • Itchy eyes
  • Diarrhea
  • Difficulty breathing
  • Drowsiness
  • Liver toxicity
  • Fatigue

These are not all the possible side effects of butterbur. As with any natural remedy, prescription or over-the-counter treatment, you should first check with your doctor before taking butterbur to learn if it might interact with anything else you’re taking, or learn if it could have a dangerous impact on any condition you have.

Who should not take butterbur?

Women who are pregnant, plan to become pregnant or nursing should not take butterbur.

People who are taking other agents that may contain toxic pyrrolizidine alkaloids or similar ingredients as butterbur, such as borage, gravel root and ragwort, should not use butterbur.

People who are allergic to plants such as ragweed, chrysanthemums, marigolds, and daisies may experience an allergic reaction to butterbur.1

As always, the best source for advice on treating your migraines is your own migraine specialist. These descriptions of natural remedies are provided only for informational purposes. You should begin no medication or supplement without first checking with your health care provider and should let them know of any other prescriptions, OTCs, and herbals you are taking to ensure there are no interactions.

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Treatment results and side effects can vary from person to person. This treatment information is not meant to replace professional medical advice. Talk to your doctor about what to expect before starting and while taking any treatment.