Quick summary

Butterbur (Petasites hybridus) is a plant traditionally used for migraine prophylaxis and allergic rhinitis. Extracts free of toxic pyrrolizidine alkaloids (PAs) have been studied in clinical contexts, especially for episodic and chronic migraine, showing potential to reduce headache frequency and disability with generally good tolerance.

What is it

Butterbur is a perennial herbaceous plant native to Europe and parts of Asia, known scientifically as Petasites hybridus. Traditionally, it has been used in herbal medicine to address conditions such as migraines and allergy symptoms.

Traditional uses

  • Migraine prevention
  • Relief of allergic rhinitis and nasal symptoms

Active compounds

Key active constituents of Butterbur include petasin and isopetasin, which are believed to contribute to its anti-inflammatory and anti-spasmodic effects. Importantly, safe clinical use requires extracts that are free of pyrrolizidine alkaloids (PAs), toxic compounds present in some unprocessed Butterbur preparations.

Potential benefits with evidence levels

Migraine prophylaxis (Moderate clinical evidence)

  • A real-world observational study involving 120 patients showed that PA-free Butterbur extract (Petadolex®) reduced headache days by 50% or more in approximately 60% of patients with episodic or chronic migraine after 12 weeks, along with reduced disability and good tolerability (Silva-Néto RP., 2026).
  • Systematic reviews and meta-analyses of randomized controlled trials indicate that higher doses of Butterbur extract may reduce migraine attack frequency and improve response rates compared to placebo, with efficacy comparable to nonsedative antihistamines used for allergic rhinitis (Agosti et al., 2006; Lim et al., 2024; Guo et al., 2007).
  • Complementary medicine reviews highlight Butterbur as a herbal nutraceutical with potential benefits for migraine prevention, supported by mechanisms including anti-inflammatory actions and inhibition of calcitonin gene-related peptide (CGRP) (Wells et al., 2019; Abo-Elghiet et al., 2025).
  • Note: Further high-quality randomized controlled trials are needed to confirm long-term effectiveness and safety.

Allergic rhinitis (Low to moderate certainty clinical evidence)

  • Systematic review and meta-analysis showed that Butterbur was among the well-studied medicinal plants for allergic rhinitis, suggesting potential improvement in nasal symptoms and rhinoconjunctivitis quality of life versus placebo, though no clear difference compared to antihistamines was observed (Lim et al., 2024).
  • Mechanistic evidence supports that bioactive metabolites like petasin may suppress immune mediators relevant to allergic rhinitis (Rahim et al., 2021).
  • Note: Evidence is limited and low to moderate certainty; more rigorous trials are needed.

Side effects

  • Mild gastrointestinal symptoms such as a bitter sensation in the mouth and eructation, reported in about 28% of patients in one study, typically lasting 2–14 days (Silva-Néto RP., 2026).
  • Potential hepatotoxicity associated with preparations containing pyrrolizidine alkaloids (PAs), including risks of hepatic sinusoidal obstruction syndrome (Teschke et al., 2021).
  • No serious adverse effects or life-threatening events have been directly attributed to PA-free Butterbur extracts in clinical studies.

Drug interactions

No strong clinical evidence exists for specific herb-drug interactions with Butterbur. However, caution is advised as with many herbal medicines:

  • Data on interactions are limited.
  • Herbal constituents may affect drug metabolism through cytochrome P450 enzymes, but effects of Butterbur are undetermined.
  • Healthcare providers typically recommend prudence when combining natural health products with conventional medications (Ogbogu et al., 2016).

Who should avoid it

  • Patients should avoid Butterbur preparations containing pyrrolizidine alkaloids due to hepatotoxicity risks.
  • Individuals with liver disease should avoid exposure to PAs.
  • Use in pregnancy and breastfeeding is not recommended due to insufficient safety data and potential risks.
  • Use in special populations should be approached with caution and under professional advice due to limited evidence.

Evidence limitations

  • Many clinical studies have methodological limitations, such as small sample sizes and short durations.
  • Potential conflicts of interest exist in some trials due to manufacturer sponsorship.
  • Variability in herbal preparations and dosing complicates comparisons across studies.
  • Long-term safety data is lacking, especially for special populations such as pregnant or breastfeeding individuals and children.
  • Observational real-world studies are uncontrolled, limiting causal conclusions.
  • Systematic reviews recommend further rigorous randomized trials using standardized PA-free extracts.

References

Last reviewed

June 2024

Disclaimer: This information is provided for educational purposes only and is not intended as medical advice. Always consult a qualified healthcare provider before starting any new herbal supplement, especially if you are pregnant, breastfeeding, have underlying health conditions, or are taking other medications.