Herbal Extract
Butterbur Extract (Petasites japonicus)
Also known as: Petasites japonicus, Japanese butterbur, Fuki, Petasin extract
Butterbur extract is a plant-derived supplement traditionally used for allergy and respiratory support, with petasins as the proposed active compounds. Clinical evidence for seasonal allergy relief is moderate, though long-term safety and efficacy data remain limited.
Last reviewed June 2026 · Evidence graded from peer-reviewed research, not editorial opinion. Educational only — not medical advice.
Primary uses
- Seasonal allergy symptom relief
- Respiratory health
- Inflammation support
- Migraine prevention
How it works
- Inhibition of leukotriene and histamine release
- Anti-inflammatory activity via petasin and isopetasin compounds
- Potential smooth muscle relaxation in airways
Dosage
- Typical range
- 50-150 mg daily (standardized extract) or as directed on label
- Timing
- With meals or as directed
- With food
- May be taken with or without food; food may reduce GI upset
- Duration
- Typically used seasonally for allergy support; 2-4 weeks may be needed for full benefit
- Special populations
- Avoid in pregnancy and lactation; limited safety data in children
Forms
- Capsule (as listed: 4:1 extract concentrate)· 70/100
- Tablet· 70/100
- Standardized extract· 70/100
Safety
Common side effects
- Gastrointestinal upset
- Headache
- Allergic reactions (rare, in sensitive individuals)
- Belching/bloating
Contraindications
- Pregnancy and lactation
- Hepatic disease (hepatotoxicity risk with certain preparations)
- Ragweed/daisy/chrysanthemum allergy (cross-reactivity possible)
- Birch pollen allergy
Evidence notes
Moderate evidence exists for butterbur in seasonal allergies from several small RCTs, though study quality is mixed and sample sizes limited. Evidence for other uses (migraines, respiratory) is more preliminary. Long-term safety data sparse, particularly regarding hepatotoxicity concerns with some plant preparations.
Grade C: Mostly observational or small trials; mechanism is plausible but unproven at scale.
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Medical disclaimer. This page is educational and does not replace advice from a qualified healthcare provider. Individual needs and risks vary — consult a professional before starting, stopping, or combining supplements, especially if you are pregnant or nursing, taking medication, or managing a health condition.