Butterbur (Petasites hybridus) is a shrub. Its large leaves were used to wrap butter during warm weather, giving it the name "butterbur".

Butterbur grows throughout Europe and parts of Asia. It's also now found in parts of the US. Butterbur contains chemicals that might relieve spasms and decrease swelling.

Butterbur is used for migraine, hay fever, asthma, and many other conditions, but there is no strong scientific evidence to support most of these uses.

Some butterbur products may contain pyrrolizidine alkaloids (PAs). These chemicals can harm the liver and cause serious side effects. Do not use butterbur products unless they are certified as free of PAs.
When taken by mouth: Butterbur products that do not contain pyrrolizidine alkaloids (PAs) are possibly safe when used for up to 16 weeks. Side effects might include belching, headache, itchy eyes, diarrhea, upset stomach, and drowsiness.

Some butterbur products may contain PAs. These products are likely unsafe. PAs can damage the liver and lungs and possibly cause cancer. Do not use butterbur products unless they are certified as free of PAs.

When applied to the skin: There isn't enough reliable information to know if butterbur is safe to use or what the side effects might be. Butterbur products that contain PAs are likely unsafe when applied to broken skin. Do not use butterbur products unless they are certified as free of PAs.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if butterbur is safe to use when pregnant or breast-feeding. Butterbur products that contain dangerous chemicals called pyrrolizidine alkaloids (PAs) are likely unsafe to use when pregnant or breast-feeding. PAs might cause birth defects and liver damage.

Children: Butterbur products that do not contain PAs are possibly safe when taken by mouth appropriately. There is some evidence that a specific PA-free butterbur rhizome extract (Petadolex, Weber & Weber, GmbH & Co) can be safely used for up to 4 months in children aged 6-17 years.

Allergy to ragweed and related plants: Butterbur may cause an allergic reaction in people who are sensitive to the Asteraceae/Compositae family. Members of this family include ragweed, chrysanthemums, marigolds, daisies, and many others. If you have allergies, be sure to check with your healthcare provider before taking butterbur.

Liver disease: Butterbur might make liver disease worse. Don't take butterbur if you have liver disease.


NatMed Pro rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.
Likely effective Effectiveness definitions
Possibly effective Effectiveness definitions
  • Hay fever. Taking a specific butterbur leaf extract called Ze 339 (Tesalin, Zeller AG) by mouth seems to decrease nose discomfort in people with hay fever. This extract might work as well as 10 mg daily of cetirizine (Zyrtec) or 180 mg daily of fexofenadine (Allegra). But this extract doesn't seem to improve airflow, nasal and eye symptoms, or quality of life when taken for 2 weeks.
  • Migraine. Taking a specific butterbur root extract (Petadolex, Weber & Weber, GmbH & Co) by mouth over 16 weeks seems to help prevent migraines in both adults and children.
Likely ineffective Effectiveness definitions
Possibly ineffective Effectiveness definitions
  • Eczema (atopic dermatitis). Taking butterbur root extract by mouth doesn't reduce symptoms of eczema.
There is interest in using butterbur for a number of other purposes, but there isn't enough reliable information to say whether it might be helpful.
Insufficient evidence Effectiveness definitions

Dosing & administration

Butterbur extracts have most often been used by adults in doses of 50-150 mg by mouth daily. Speak with a healthcare provider to find out what dose might be best for a specific condition.

Some butterbur products may contain pyrrolizidine alkaloids (PAs). These products are likely unsafe. Do not use butterbur products unless they are certified and labeled as free of PAs.

Interactions with pharmaceuticals

Medications that increase break down of other medications by the liver (Cytochrome P450 3A4 (CYP3A4) inducers)

Interaction Rating=Moderate Be cautious with this combination.

Butterbur is changed and broken down by the liver. Some drugs increase how quickly the liver changes and breaks down butterbur. This could change the effects and side effects of butterbur.

Interactions with herbs & supplements

Herbs that increase the breakdown of other herbs by the liver: Some herbs affect the way the liver processes chemicals such as pyrrolizidine alkaloids (PAs). These herbs might cause the liver to turn PAs into chemicals that are even more poisonous. Herbs that can affect the liver in this way include echinacea, garlic, licorice, St. John's wort, and schisandra.
Pyrrolizidine alkaloids (PAs)-containing herbs and supplements: Butterbur contains PAs, dangerous chemicals that can harm the liver. Taking it along with other supplements that also contain these chemicals might increase the chance of developing serious side effects, including liver damage and cancer. Examples of supplements containing PAs include alkanna, coltsfoot, comfrey, and groundsel.

Interactions with foods

There are no known interactions with foods.
vital.ly has licensed monographs from TRC Healthcare.
This monograph was last reviewed on 29/06/2023 10:00:00 and last updated on 24/07/2020 01:38:16. Monographs are reviewed and/or updated multiple times per month and at least once per year.
Natural Medicines disclaims any responsibility related to medical consequences of using any medical product. Effort is made to ensure that the information contained in this monograph is accurate at the time it was published. Consumers and medical professionals who consult this monograph are cautioned that any medical or product related decision is the sole responsibility of the consumer and/or the health care professional. A legal License Agreement sets limitations on downloading, storing, or printing content from this Database. No reproduction of this monograph or any content from this Database is permitted without written permission from the publisher. It is unlawful to download, store, or distribute content from this site.