SO DYK
The curious few.
50 founding spots left

Know what you're putting in your body.

158 herbs, nutrients, and compounds. What the science says, what tradition knew, and what to watch for. Founding members keep this running.

$60 /year

Founding rate — locked for life. Regular price after launch: $96/year.

  • ✓ Full access to all 158+ entries
  • ✓ Print-ready reference card for every herb
  • ✓ Monthly curated set — 5 herbs, one body system
  • ✓ The Sunday Letter — weekly research digest
  • ✓ Bookmarks synced across devices
  • ✓ Founding rate locked forever
Become a founding member

Cancel any time. No questions asked.

GUT HEALTH

Butterbur

Petasites hybridus

also known as petasites

Moderate (migraine and allergy) — but only PA-free preparations are safe

A large-leaved European wetland plant used since ancient Greek medicine. Butterbur has real evidence for two specific uses — migraine prevention and seasonal allergies — but the raw plant contains pyrrolizidine alkaloids that cause serious liver injury. Only PA-free standardized preparations are appropriate for use, and even those have come under scrutiny.

  • Real evidence for reducing migraine frequency when taken consistently — comparable to some prescription preventives in studies
  • Eases seasonal allergy symptoms (hay fever) — runny nose, itchy eyes, congestion
  • Long traditional European use for cough, fever, and pain
  • Petadolex, a standardized PA-free butterbur extract, has been the most-studied preparation
  • Most modern butterbur research uses pharmaceutical-grade PA-free extracts
Only use PA-free standardized preparations — raw butterbur and unverified products contain pyrrolizidine alkaloids that cause irreversible liver damage and have caused liver failure
Even PA-free preparations have caused liver injury reports — in 2012, German and UK regulators withdrew several butterbur products over hepatotoxicity concerns
Skip with pre-existing liver conditions
Skip during pregnancy and nursing
Possible cross-reactivity with ragweed and daisy-family allergies
Use caution with medications metabolized by the liver
Stop and seek medical attention if jaundice, dark urine, or right-side abdominal pain develop
Periodic liver function testing is reasonable for anyone using butterbur consistently

NCCIH — Butterbur · MedlinePlus Herbs & Supplements · NIH NCCIH Herbs at a Glance

You might also explore
The curious few.
50 founding spots left

Know what you're putting in your body.

158 herbs, nutrients, and compounds. What the science says, what tradition knew, and what to watch for. Founding members keep this running.

$60 /year

Founding rate — locked for life. Regular price after launch: $96/year.

  • ✓ Full access to all 158+ entries
  • ✓ Print-ready reference card for every herb
  • ✓ Monthly curated set — 5 herbs, one body system
  • ✓ The Sunday Letter — weekly research digest
  • ✓ Bookmarks synced across devices
  • ✓ Founding rate locked forever
Become a founding member

Cancel any time. No questions asked.