Compound or practice · Supplement
Butterbur
Solid evidence for migraine prevention and allergic rhinitis — but only PA-free products are safe.
- Overall grade
- Grade B
- Last revised
- 2
- graded outcomes
- 0
- references listed
A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.
3 at grade B — 3 graded rows
What is known
Each outcome with its grade (how strong the evidence is, A to D), the size of the effect where the entry records one, and how often studies agree.
- Migraine preventionEvidence grade B
PA-free extract
Moderatehigh
- Allergic rhinitisEvidence grade B
Antihistamine-comparable in trials
Moderatemixed
Conditions
How the entry reads its effect on diagnosed conditions: the direction first, then the grade. Never a substitute for the person who treats you.
- Migraine ImprovesEvidence grade BPA-free onlyGrade B
What is uncertain
Read off the same rows as above. Nothing here is added that the entry does not itself record.
- Studies disagree: Allergic rhinitis (mixed agreement).
The evidence in words
What it is
Butterbur (Petasites hybridus) is used for migraine prevention and hay fever; only preparations free of toxic pyrrolizidine alkaloids (PA) are safe.
How it works
Petasin compounds have anti-inflammatory and smooth-muscle effects relevant to migraine and allergy.
What the evidence shows
Grade B for migraine prophylaxis (a standardized extract, Petadolex, has positive RCTs; some guidelines endorsed it before PA-safety concerns) and reasonable for allergic rhinitis. The overriding issue is liver-toxic PAs in unpurified products.
How to use it
Only certified PA-free standardized extract (e.g., 50–75 mg twice daily for migraine).
Safety & interactions
PA-containing products are hepatotoxic and carcinogenic — use only PA-free certified extracts.
Bottom line
Genuinely effective for migraine and hay fever, but ONLY as a certified PA-free product — otherwise it can damage the liver.
How it is used
As the entry records it, from the studies it summarises. Not a recommendation for you — doses that suit a trial population may not suit you.
- Standard
- PA-free extract, 50–75 mg twice daily.
Related reading
Entries that share this one's tags or conditions.
- Butterbur for MigraineEvidence grade B — PA-free onlyEvidence grade B
- Butterbur for Allergic rhinitisEvidence grade B — Antihistamine-comparable in trialsEvidence grade B
- Butterbur for Migraine preventionEvidence grade B — PA-free extractEvidence grade B
- Butterbur: dosage and how to take itPA-free extract, 50–75 mg twice daily.Evidence grade B
Sources
This entry lists no references of its own.
Last revised . A grade is this entry's reading of the evidence, not medical advice.