Petasites hybridus (L.) G.Gaertn., B.Mey. & Schreb.

P. officinalis Moench; P. vulgaris Desf.; Tussilago hybrida L.; T. petasites L.; and others

Asteraceae (Compositae)

Petasites; purple butterbur; sweet coltsfoot

Petasitidis folium

Leaf (rhizome and radix are also used occasionally)

The main constituents are the sesquiterpenes petasin and isopetasin, volatile oils, flavonoids and tannins (Aydin et al. 2013; Prieto 2014). Toxic pyrrolizidine alkaloids are present in the fresh plant, but preparations for internal use need to have these removed.

For migraine prophylaxis, two clinical trials have shown that 25 mg of standardised Petasites extract (in capsule form) twice daily for 12 weeks can significantly reduce the frequency and duration of migraine attacks compared to placebo, with no adverse reactions (Grossman and Schmidramsl 2001; Diener et al. 2004). However, a three-arm, parallel group, randomised trial comparing Petasites extract (75 mg and 50 mg twice daily) with placebo over 4 months found that only the higher dose of extract was more effective than placebo (Lipton et al. 2004). Overall, the clinical evidence is promising (Prieto 2014), but systematic reviews suggest that there is only moderate evidence for its effectiveness in migraine prophylaxis. Further studies on dose/day and the products’ efficacy are needed (Agosti et al. 2006; Sun-Edelstein and Mauskop 2009).

Butterbur extracts have also shown encouraging results for the treatment of seasonal allergic rhinitis (Schapowal 2005), and a similar effect was observed in a post-marketing surveillance study for a specific extract, which was found to be safe and efficacious at a dose of two tablets daily for 2 weeks (8 g petasins per tablet; Kaufeler et al. 2006; Guo et al. 2007: review).