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ingestible · for seasonal allergies

Butterbur Extract Ze 339

Reviewed by the Nimbera editorial team · Last updated May 2026

Schapowal et al. (n=330) RCT comparing Ze 339 to fexofenadine and placebo found both active arms significantly superior to placebo (p<0.001) with no difference between them. PMID 16114089. A prior landmark BMJ RCT (n=125, PMID 11799030) found butterbur similarly effective to cetirizine without sedative side effects.$20-$40 per month

How to use

Take one tablet of a standardised Ze 339 extract (8 mg petasins per tablet) twice daily during pollen season. Use only PA-free (pyrrolizidine alkaloid-free) certified products.

How it works

Petasin and isopetasin, the active sesquiterpenes in butterbur, inhibit leukotriene and histamine synthesis and block calcium channels involved in smooth-muscle contraction and mast-cell degranulation.

Where to buy

Health food stores and online retailers; look for brands that certify PA-free status such as Tesalin or Petadolex.

Typical cost: $20-$40 per month

Safety notes

Use only PA-free certified extracts - unpurified butterbur contains pyrrolizidine alkaloids that are hepatotoxic. Avoid if allergic to ragweed or other Asteraceae plants. Not for use in pregnancy or in children under 12 without medical supervision.

Drug & supplement interactions

  • Always tell your doctor or pharmacist about any supplements you take.
  • Interactions can occur with prescription medications, blood thinners, and immunosuppressants.
  • Herbal remedies can affect how the body absorbs or metabolises drugs.
  • Check drugs.com interactions checker before starting.

Clinical source

Schapowal A et al., Treating intermittent allergic rhinitis: Ze 339 vs fexofenadine vs placebo, Phytotherapy Research, 2005

This information is compiled from primary clinical literature and is for informational purposes only. It is not a substitute for professional medical advice. Read our full disclaimer.