Botanical

Butterbur

Petasites hybridus

Evidence TierCWADA NOT PROHIBITED

tuneTypical Dose

Total daily dose of 150 mg from standardized PA-free extract in divided doses

watchEffect Window

Migraine-prevention effects were assessed over months, not days.

check_circleCompliance

WADA NOT PROHIBITED

Overview

Clinical Summary

PA-free butterbur extract has older evidence for migraine prevention and seasonal-allergy symptom relief, but safety concerns make it a cautious choice rather than a routine recommendation.

Butterbur has real human trial data, but its risk profile limits how confidently it should be recommended. Older standardized PA-free extracts improved migraine attack frequency and seasonal allergic rhinitis symptoms in randomized trials. The main problem is safety. Butterbur products can contain hepatotoxic pyrrolizidine alkaloids unless they are carefully purified, and even PA-free products have generated liver safety concerns.

Butterbur extracts are discussed mainly for anti-inflammatory and leukotriene-modulating effects. The clinical evidence is real but older, extract specific, and overshadowed by safety concerns around pyrrolizidine alkaloids and liver toxicity.

Outcomes

What This Is Expected To Influence

Primary Outcomes

  • Migraine prevention with standardized PA-free extract

Secondary Outcomes

  • Seasonal allergic-rhinitis symptom relief

Safety

Contraindications and Interactions

Contraindications

  • Liver disease
  • Pregnancy

Side effects

  • Burping or GI upset

Interactions

  • Hepatotoxic drugs

Avoid if

  • You cannot verify the product is certified PA-free
  • You want a low-risk daily supplement

Evidence

Study-level References

but-SRC-001Randomized controlled trial
Sourceopen_in_new

Lipton RB, et al. Petasites hybridus root (butterbur) is an effective preventive treatment for migraine. Neurology. 2004. doi:10.1212/01.WNL.0000147290.68260.11. PMID:15623680.

Population: Adults aged 18 to 65 years with migraine and at least two to six attacks per month.

Dose protocol: 75 mg twice daily PA-free extract for 4 months

Key findings: Reduced migraine attack frequency versus placebo.

Notes: Best direct migraine RCT.

Paper content

This is the most important butterbur migraine trial. The 75 mg twice-daily PA-free extract outperformed placebo over 4 months, supporting a real migraine-prevention effect for that specific formulation.

but-SRC-002Systematic review
Sourceopen_in_new

Guo R, et al. Herbal medicines for the treatment of allergic rhinitis: a systematic review. Ann Allergy Asthma Immunol. 2007. PMID:18219828.

Population: Double-blind randomized trials of herbal medicines for allergic rhinitis.

Dose protocol: Trial specific across allergic-rhinitis studies

Key findings: Review found several positive allergic-rhinitis trials.

Notes: Useful for allergy framing.

Paper content

This review is useful because it summarizes the older allergic-rhinitis butterbur trials. The evidence suggests symptomatic benefit is possible, but the practical use case is limited by the product safety issue.

but-SRC-003Systematic review.
Sourceopen_in_new

Braunwalder C, Ertl J, Wullschleger M, Timm E, Wolf U. Efficacy and Safety of Phytotherapy and Anthroposophic Medicine in Seasonal Allergic Rhinitis: A Systematic Review. Int Arch Allergy Immunol. 2025;186(1):75-86. doi:10.1159/000539645. PMID:39084196.

Population: Adults and adolescents with seasonal allergic rhinitis across 14 clinical studies.

Dose protocol: Various butterbur preparations across 14 SAR clinical studies

Key findings: Butterbur demonstrated beneficial effects across symptom and nasal airflow measures with a favorable safety profile.

Notes: Recent systematic review reinforcing butterbur as the most studied phytotherapy for SAR.

Paper content

This systematic review examined 14 clinical studies of herbal preparations for seasonal allergic rhinitis. Petasites hybridus (butterbur) was the most studied plant and demonstrated beneficial effects across symptom relief and nasal airflow measures. About half of the included studies were rated as sufficient quality. The review confirms butterbur as a promising phytotherapy option for SAR with a favorable safety profile among studied preparations. Limitations include the heterogeneity of study designs and the variable quality of included evidence.

but-SRC-004Systematic review and meta-analysis.
Sourceopen_in_new

Lim XY, Lau MS, Zolkifli NA, et al. Medicinal plants for allergic rhinitis: A systematic review and meta-analysis. PLoS One. 2024;19(4):e0297839. doi:10.1371/journal.pone.0297839. PMID:38603736.

Population: Adults and children with allergic rhinitis across 29 RCTs (1879 participants).

Dose protocol: 29 RCTs of medicinal plants for allergic rhinitis (butterbur most studied with 5 trials)

Key findings: Plants reduced nasal symptoms (SMD -0.31 vs placebo) and improved quality of life. No clear difference versus antihistamines.

Notes: Large meta-analysis positioning butterbur within broader herbal allergy evidence.

Paper content

This meta-analysis pooled 29 RCTs (1879 participants) of single medicinal plant treatments for allergic rhinitis. Butterbur was the most frequently studied plant (5 trials). Plants showed a small reduction in nasal symptoms versus placebo (SMD -0.31) and improved quality of life (MD -0.46). Moderate-certainty evidence showed no clear difference between medicinal plants and antihistamines for overall symptom control. The review concludes that while signals exist, clear beneficial evidence remains lacking and better-designed trials are needed. The study is valuable for positioning butterbur within the broader herbal allergy evidence base.

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