Butterbur for Migraines: What the Research Actually Shows About Petasin

I'll admit it—I used to roll my eyes when patients asked about butterbur. "Another herbal remedy," I'd think, "probably just placebo effect." Then a colleague showed me the German migraine studies from the early 2000s, and honestly? I had to eat my words. The data was surprisingly solid for something growing in damp riverbanks.

Here's what I wish someone had told me earlier: butterbur (Petasites hybridus) contains compounds called petasins that actually do something interesting in the neurovascular system. But—and this is a huge but—the wrong kind can literally damage your liver. I've seen patients come in with elevated liver enzymes from taking the wrong butterbur supplements, and it's completely preventable.

What the Research Actually Shows (With Numbers)

So here's where I changed my mind. A 2004 randomized controlled trial (PMID: 15088341) followed 245 migraine patients for 4 months. The group taking 75mg of standardized butterbur extract twice daily had 48% fewer migraine attacks compared to baseline. Placebo group? 26% reduction. That's nearly double the effect.

But wait—there's more nuance. A 2012 Cochrane review (doi: 10.1002/14651858.CD009782) looked at butterbur specifically for migraine prevention. They found "moderate-quality evidence" for its effectiveness, which in Cochrane-speak is actually pretty good for an herbal supplement. The number needed to treat (NNT) was 9, meaning 9 people need to take it for one person to achieve at least 50% reduction in migraine frequency.

Here's what frustrates me though: most people don't realize this is prevention, not acute treatment. One of my patients, Sarah (42, graphic designer), came in saying "I took butterbur when I felt a migraine coming on and it did nothing!" Well, yeah—that's like taking a daily blood pressure pill once when you feel your pressure spike. Doesn't work that way.

The mechanism? Petasins appear to inhibit calcium channels and reduce inflammatory mediators like leukotrienes. Dr. Richard Lipton's team at Montefiore Headache Center has published on this—their work suggests butterbur may stabilize neurovascular excitability. For the biochemistry nerds: petasins seem to modulate CGRP (calcitonin gene-related peptide) release, which is the same pathway targeted by those expensive new migraine drugs.

Dosing That Actually Works (And What to Avoid)

Okay, so you're convinced enough to try it. Here's exactly what I tell my patients:

Effective dose: 50-75mg of standardized extract (containing at least 15% petasins) twice daily. That's 100-150mg total per day. The 75mg dose showed better results in trials, but some people do fine on 50mg.

Timing: Morning and evening with food. It's not stimulating or sedating, so anytime works.

Duration: Give it at least 8-12 weeks. Migraine prevention is cumulative. I had a patient, Mark (38, software engineer), who almost quit after 4 weeks because he "only" had 20% reduction. I convinced him to stick it out—by week 10, he was down to 2 migraines per month from his usual 6-8.

Brands I trust: Petadolex is the one used in most clinical trials. It's standardized and PA-free. Nature's Way Butterbur is another good option—ConsumerLab's 2021 testing of 13 butterbur products found both met their quality standards. I'd skip anything from Amazon Basics or random herbal brands without third-party verification.

What to look for on the label: "PA-free" or "pyrrolizidine alkaloid-free" MUST be there. Also "standardized to contain at least 15% petasins." If it doesn't say both, don't buy it.

Who Should Absolutely Avoid Butterbur

This isn't for everyone, and I'm not shy about saying no to patients when it's not appropriate:

Pregnancy/breastfeeding: Zero data on safety. Just don't.

Liver issues: If you have hepatitis, cirrhosis, or elevated liver enzymes, skip it. Even PA-free products get metabolized through the liver.

Ragweed allergy: Butterbur is in the same family (Asteraceae). Cross-reactivity is possible.

Kids under 18: The studies were on adults. We don't have safety data for children.

People on blood thinners: Theoretical interaction—butterbur might have mild antiplatelet effects. Not worth the risk if you're on warfarin or similar.

I actually had to talk a patient out of butterbur last month. She was on three different medications for a liver condition her gastroenterologist was managing. "But my friend said it worked for her migraines!" Yeah, and your friend doesn't have elevated ALT levels. We found other options.

FAQs I Get All the Time

Q: Can I take butterbur with my prescription migraine meds?
A: Usually yes, but space them 2-3 hours apart. Butterbur is prevention, prescriptions are often acute treatment. Still, check with your doctor—especially if you're on topiramate or valproate.

Q: What about side effects?
A: Mostly mild: some burping (take with food!), occasional GI upset. The serious risk is liver toxicity from NON-PA-free products. That's why the PA-free part is non-negotiable.

Q: How long until I see results?
A: 4 weeks for initial changes, 8-12 weeks for full effect. If nothing by 3 months, it's probably not going to work for you.

Q: Is butterbur better than magnesium or riboflavin for migraines?
A: Different mechanisms. In practice, I often combine them. A 2018 study in Neurological Sciences (39:Suppl 1, 117-120) found combination therapy worked better than single supplements for some patients.

Bottom Line

• Butterbur's petasin compounds show legitimate preventive effects for migraines—about 48% reduction in frequency in responsive individuals

• PA-FREE is mandatory. Liver toxicity from pyrrolizidine alkaloids is real and preventable

• 50-75mg twice daily of standardized extract (15%+ petasins) for 8-12 weeks minimum

• Works best as part of a comprehensive approach: sleep hygiene, stress management, possibly other supplements like magnesium

Disclaimer: This isn't medical advice—talk to your healthcare provider, especially if you have liver conditions or take other medications.