Butterbur for Migraine prevention

Evidence grade B — PA-free extract

Assembled by the app from other entries in this library. It adds no evidence of its own — follow the links to the entries it draws on.

1 at grade B — 1 graded row

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.

Outcome	Grade	Effect size	Agreement
Migraine preventionPA-free extract	Evidence grade B	Moderate	high

For migraine prevention, Butterbur earns evidence grade B (moderate effect, high consistency) — there is real evidence here. PA-free extract

Petasin compounds have anti-inflammatory and smooth-muscle effects relevant to migraine and allergy.

Only certified PA-free standardized extract (e.g., 50–75 mg twice daily for migraine).

PA-containing products are hepatotoxic and carcinogenic — use only PA-free certified extracts.

Genuinely effective for migraine and hay fever, but ONLY as a certified PA-free product — otherwise it can damage the liver.

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.

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: dosage and how to take itPA-free extract, 50–75 mg twice daily.Evidence grade B
Butterbur: side effects, safety & interactionsPA-containing products are hepatotoxic and carcinogenic — use only PA-free certified extracts.Evidence grade B

This entry lists no references of its own — it is assembled from the entries it links to, whose sources are on their pages.

Last revised Jul 10, 2026. A grade is this entry's reading of the evidence, not medical advice.