Butterbur extract (Petadolex® — PA-free) is one of the best-evidenced herbal migraine preventives. A 2004 RCT found 150mg/day reduced migraine frequency by 48% — comparable to prescription preventives. The active petasins are anti-inflammatory and antispasmodic. CRITICAL: raw butterbur contains pyrrolizidine alkaloids (PAs) — hepatotoxic and carcinogenic. ONLY use PA-free extracts (Petadolex). Germany and UK withdrew butterbur products over PA contamination concerns. Our assessment: highly effective but ONLY with certified PA-free products. --- *Reviewed by the Dose AI Research Team and Clinical Advisory Board* *Last updated: 2026-04-06*
Reviewed by the Scan Dose Research Team and Clinical Advisory Board | Last updated:
Not medical advice. Based on published clinical research and systematic reviews.