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© Steven Foster

Common Names: butterbur, petasites, purple butterbur

Latin Names: Petasites hybridus (also known as Petasites officinalis or Tussilago hybrida)


  • Butterbur is a shrub that grows in Europe and parts of Asia and North America. The name, butterbur, is attributed to the traditional use of its large leaves to wrap butter in warm weather.
  • In the Middle Ages butterbur was used for plague and fever, and in the 17th century it was used to treat cough, asthma, and skin wounds. More recently, it has been promoted as a dietary supplement for urinary tract symptoms, stomach upset, headaches including migraines, allergic rhinitis (hay fever), and other conditions.

How Much Do We Know?

  • There have been a few studies of butterbur for migraines and allergic rhinitis (hay fever) in people, so we have some knowledge of its effects on these two conditions.

What Have We Learned?

  • Butterbur appears to help reduce the frequency of migraines in adults and children. In 2012, the American Academy of Neurology recommended its use for preventing migraines. However, the Academy stopped recommending it in 2015 because of serious concerns about possible liver toxicity.
  • Some studies of butterbur root or leaf extracts suggest that they may be helpful for symptoms of hay fever (allergic rhinitis), but the data are not convincing.
  • One study suggested that a combination product containing butterbur might improve anxiety and depression in people with somatoform disorders. (Somatoform disorders are characterized by physical complaints for which no physiological explanation is found and for which psychological factors are likely involved.)
  • Butterbur has not been proven helpful for allergic skin reactions, chronic obstructive bronchitis, insomnia, upset stomach, urinary tract symptoms, asthma, and other conditions.

What Do We Know About Safety?

  • Some butterbur products contain chemicals called pyrrolizidine alkaloids (PAs). PAs can damage the liver, lungs, and blood circulation, and possibly cause cancer. Only butterbur products that have been processed to remove PAs and are labeled or certified as PA-free should be considered for use.
  • Some countries have withdrawn butterbur products from the market because of concerns about liver toxicity.
  • Some experts recommend that butterbur not be used for treating migraine because of its safety concerns.
  • Not enough is known about whether it’s safe to apply butterbur products to the skin.
  • Several studies, including a few studies of children and adolescents, have reported that PA-free butterbur products seem to be safe when taken by mouth in recommended doses for up to 16 weeks. However, some products claiming to be PA-free may not in fact be. For example, Petadolex is marketed as a PA-free butterbur product, but it has been associated with liver damage in some people, suggesting that it may have had PAs. Also, the safety of longer-term use of butterbur has not been established.
  • Butterbur products with PAs should not be used during pregnancy or while breastfeeding because they may cause birth defects or liver damage. Little is known about whether it’s safe to use PA-free butterbur during pregnancy or while breastfeeding.
  • PA-free butterbur is generally well tolerated but can cause side effects such as belching, headache, itchy eyes, diarrhea, breathing difficulties, fatigue, upset stomach, and drowsiness.
  • Butterbur may cause allergic reactions in people who are sensitive to plants such as ragweed, chrysanthemums, marigolds, and daisies.
  • If you’re planning to use butterbur or to give it to your child, tell your (or the child’s) health care provider. Health care providers may consider liver function monitoring for people using butterbur.

Keep in Mind

  • Take charge of your health—talk with your health care providers about any complementary health approaches you use. Together, you can make shared, well-informed decisions.

For More Information

NCCIH Clearinghouse

The NCCIH Clearinghouse provides information on NCCIH and complementary and integrative health approaches, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

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A service of the National Library of Medicine, PubMed® contains publication information and (in most cases) brief summaries of articles from scientific and medical journals. For guidance from NCCIH on using PubMed, see How To Find Information About Complementary Health Approaches on PubMed.


Office of Dietary Supplements (ODS), National Institutes of Health (NIH)

ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public. Its resources include publications (such as Dietary Supplements: What You Need To Know) and fact sheets on a variety of specific supplement ingredients and products (such as vitamin D and multivitamin/mineral supplements).


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Key References

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NCCIH has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your health care provider(s). We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCIH.

Last Updated: July 2020