The short spikes of flowers are produced just before the leaves in spring, emerging with only a few elongated basal bracts and are usually green, flesh coloured or dull white depending on the species.
Butterbur extracts may contain harmful components called pyrrolizidine alkaloids if the preparations are not carefully and fully purified. The concentration of the toxic alkaloids is often highest in the rhizomes and lowest in the leaves, and may vary depending on where the plants are grown. These chemicals are toxic to the liver and may cause cancers. Thus, due to the potential for contamination, taking butterbur supplements is not recommended during pregnancy or breastfeeding. It is safe practice to consume butterbur extract that has been prepared by a reputable laboratory.
Long-term health effects and interaction of butterbur with other drugs have not been well documented. However, it can theoretically interact with certain blood pressure and heart medications, as well as with drugs that can induce a liver enzyme called CYP3A4 (i.e. St. John's Wort, carbamazepine, phenytoin, rifampin); this interaction can potentially lead to increased concentration of the toxic alkaloids.
Butterbur has been used for over 2000 years to treat a variety of ailments including fever, lung disease, spasms, and pain. Currently, butterbur extract is used for migraine prevention and treatment of allergic rhinitis, which have the most evidence for its effectiveness. Some butterbur species contain the chemicals petasin and isopetasin which are believed to have potential benefits in treating migraines. High concentrations of petasin occur in both butterbur root and leaves, with the leaves containing lower levels of the toxic chemical. Butterbur extracts have been reported to be effective in reducing frequency and severity of migraine headaches. Several double-blind studies have shown that high doses of Petasites hybridus" extract, containing petasin and/or isopetasin, are effective both in preventing and in relieving migraine, with the best results in groups taking the higher dose of the supplement. Although mainly well-tolerated, the adverse effects of butterbur reported in clinical trials include mainly gastrointestinal problems, such as nausea, flatulence, and belching. The American Academy of Neurology and American Headache Society now endorse butterbur for preventing migraine headaches with a Level A recommendation (based on at least two strong clinical trials). Furthermore, the Canadian Headache Society supports a strong recommendation for use of butterbur in prevention of migraines for select patients based on their clinical features and co-existing disorders.
Additionally, a study showed butterbur extract to be an effective treatment for hay fever without the sedative effect of the antihistamine cetirizine, if taken four times daily. Butterbur was also shown to be comparably effective as fexofenadine when compared to placebo for reducing symptoms of allergic rhinitis.
- Petasites albus White Butterbur - Europe, Algeria, Turkey, Caucasus, India
- Petasites fominii - Republic of Georgia
- Petasites formosanus - Taiwan
- Petasites frigidus Arctic Butterbur or Arctic Sweet Coltsfoot - Scandinavia, Mongolia, Canada, northern USA
- Petasites hybridus Common Butterbur - Europe, Mediterranean
- Petasites japonicus Giant Butterbur, or Fuki - China, Japan, Korea
- Petasites kablikianus - southeastern Europe from Poland to Albania
- Petasites kamengicus - Arunachal Pradesh
- Petasites paradoxus - central + southwestern Europe from Spain to Poland
- Petasites pyrenaicus from Azores to Ireland + Tunisia
- Petasites radiatus - Mongolia
- Petasites rubellus - Mongolia, Manchuria, Korea
- Petasites sibiricus - Siberia
- Petasites spurius - Europe, Siberia, Caucasus, Central Asia
- Petasites tatewakianus - Siberia, Russian Far East, northeastern China
- Petasites tricholobus - China, Vietnam, Himalayas
- Petasites versipilus - Sichuan, Yunnan
- Species of hybrid origin
- Petasites × vitifolius
- Species formerly included
Petasites glacialis (Ledeb.) Polunin - Endocellion glaciale (Ledeb.) Toman
- Flann, C (ed) 2009+ Global Compositae Checklist
- Miller, Philip. 1754. Gardeners Dictionary...Abridged...fourth edition page 1056.
- Tropicos, Petasites Mill.
- "Missouri Botanical Garden".
- Sun-Edelstein, Christina (March 2011). "Alternative Headache Treatments: Nutraceuticals, Behavioral and Physical Treatments". Headache 51 (3): 469–483. doi:10.1111/j.1526-4610.2011.01846.x. PMID 21352222. Retrieved 3 November 2014.
- Sutherland, Anna; Sweet, Burgunda (May 2010). "Butterbur: An alternative therapy for migraine prevention". American Journal of Health System Pharmacy 67 (9): 705–711. doi:10.2146/ajhp090136. PMID 20410544.
- "Petasites in Flora of North America -Vol. 20 Page 635 Petasites Miller, Gard. Dict. Abr. ed. 4. vol. 3. 1754". efloras.org.
- "Petasites in Flora of China - Vol. 20-21 Page 461 蜂斗菜属 feng dou cai shu Petasites Miller, Gard. Dict. Abr., ed. 4. . 1754". efloras.org.
- Altervista Flora Italiana genere Petasites
- Taylor, Frederick (March 2011). "Nutraceuticals and Headache: The Biological Basis". Headache 51 (3): 484–501. doi:10.1111/j.1526-4610.2011.01847.x.
- Maxim Hirono I., Mori H., Yamada K. "Carcinogenic activity of petasitenine, a new pyrrolizidine alkaloid isolated from Petasites" Journal of the National Cancer Institute 1977 58:4 (1155-1157)
- Smith, LW; Culvenor, CC (1981). "Plant sources of hepatotoxic pyrrolizidine alkaloids". Journal of Natural Products 44 (2): 129–52. doi:10.1021/np50014a001. PMID 7017073.
- "Butterbur". Facts & Comparisons.
- "Evidence-based guideline update: NSAIDs and other complementary treatments for episodic migraine prevention in adults. Report of the Quality Standards Subcommittee of the American Academy of Neurology and the American Headache Society.". Quality Standards Subcommittee of the American Academy of Neurology and the American Headache Society. Neurology 2012 Apr 24;78(17):1346-53. Retrieved 2012-10-02.
- Kaufeler, Robert; Polasek, Wolfgang; Brattstrom, Axel; Koetter, Uwe (March 2006). "Efficacy and Safety of Butterbur Herbal Extract Ze 339 in Seasonal Allergic Rhinitis: Postmarketing Surveillance Study". Advances in Therapy 23 (2): 373–384. doi:10.1007/bf02850143. PMID 16751170.
- Lipton RB, Göbel H, Einhäupl KM, Wilks K, Mauskop A (December 2004). "Petasites hybridus root (butterbur) is an effective preventive treatment for migraine". Neurology 63 (12): 2240–4. doi:10.1212/01.wnl.0000147290.68260.11. PMID 15623680.
- Pringsheim, Tamara; Davenport, Jeptha; Mackie, Gordon (March 2012). "Canadian Headache Society Guideline for Migraine Prophylaxis". Canadian Journal of Neurological Sciences 39 (2): 1–62. PMID 22683887.
- Schapowal, A.Schapowal A; Petasites Study, Group (19 January 2002). "Randomised controlled trial of butterbur and cetirizine for treating seasonal allergic rhinitis". BMJ 324 (7330): 144–6. doi:10.1136/bmj.324.7330.144. PMC 64514. PMID 11799030.
- Schapowal, Andreas (2005). "Treating Intermittent Allergic Rhinitis: A Prospective, Randomized, Placebo and Antihistamine-controlled Study of Butterbur Extract Ze 339". Phytotherapy Research 19 (6): 530–537. doi:10.1002/ptr.1705. PMID 16114089.
- "Search results — The Plant List". theplantlist.org.
- Clapham, A.R., Tutin, T.G. and Warburg. 1968. Excursion Flora of the British Isles. Cambridge University Press. ISBN 0-521-04656-4
- Parnell, J. and Curtis, T. 2012. Webb's An Irish Flora. Cork University Press. ISBN 978-185918-4783
- Flora Europaea: Petasites species list and distributions
- eFloras search results: Petasites
- Edibility of Petasites: Visual identification and edible parts of sweet coltsfoot.