The feverfew trial that worked used a standardised extract at 6.25 mg 3 times a day, while a typical capsule holds 1000 mg. The 2 are not comparable.
One is a standardised CO2 extract and the other is dried herb. A bigger number on the label is not a bigger dose of what was tested.
Quick Answer: How Much Feverfew Should You Take?
The positive trial used a standardised feverfew CO2 extract at 6.25 mg three times daily, which is 18.75 mg a day, for 16 weeks. A typical capsule of dried feverfew herb contains 1000 mg, which is a different preparation rather than a larger dose. Match the form first and the number second.
Key Takeaways
- The positive trial used 6.25 mg of CO2 extract, 3 times daily.
- That comes to 18.75 mg a day, taken across 16 weeks.
- A typical herb capsule contains 1000 mg of dried feverfew.
- Those 2 are different preparations, not different sizes of 1 thing.
- Cochrane could not pool its 6 trials because the forms varied.
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The Two Numbers
Almost every dosing table online mixes these up, and the mix-up makes the whole category confusing.
| Standardised CO2 extract | Dried feverfew herb | |
|---|---|---|
| What it is | A concentrated fraction | The ground plant |
| Trial amount | 6.25 mg, 3 times daily | Not the trial preparation |
| Daily total | 18.75 mg | Commonly 1000 mg |
| Standardised to | A defined extract specification | Usually nothing |
| Evidence | The trial Cochrane called rigorous | Included in older trials |
Comparing 18.75 mg with 1000 mg as if they were the same scale is the error. What feverfew is comes first, in what feverfew actually is.
Why Cochrane Could Not Pool
This is the practical consequence of the form problem, and it is stated plainly in the review.
- Trials: 6, covering 561 patients.
- Reporting frequency: 5 of the 6.
- Pooled analysis: Not possible.
- Why: Different outcome measures, participants and interventions.
When trials use different preparations of the same plant, they are not really testing the same thing, which is why the numbers refuse to combine.[1]Feverfew for preventing migraine — Cochrane Database of Systematic Reviews (2015) View source A 2025 meta-analysis did manage to pool 9 trials, at the cost of high heterogeneity.
What the Trial Protocol Looked Like
If you want to reproduce the result, this is what it took.
| Element | The trial |
|---|---|
| Preparation | Feverfew CO2 extract |
| Dose | 6.25 mg three times daily |
| Baseline period | 4 weeks of recording first |
| Treatment period | 16 weeks |
| Result | 0.6 attacks a month better than placebo |
| Adverse events | 8.4% against 10.2% on placebo |
The 4-week baseline matters as much as the dose, because you cannot judge a 0.6-attack difference without knowing your own starting number.[2]Efficacy and safety of 6.25 mg t.i.d. feverfew CO2-extract (MIG-99) in migraine prevention - a randomized, double-blind, multicentre, placebo-controlled study — Cephalalgia (2005) View source The full result is in the migraine trial data.
Parthenolide and Standardisation
Most labels reference parthenolide, and it is worth knowing what that does and does not tell you.
- What it is: A compound found in feverfew leaves.
- Used as: A marker for standardising extracts.
- Proven active: Not established as the sole active compound.
- On our label: 1000 mg of herb, without a parthenolide figure.
A parthenolide percentage tells you a manufacturer measured something. It does not tell you the product matches the extract used in the trial.
A Practical Approach
Short, and mostly about what to record rather than what to swallow.
| Step | Detail |
|---|---|
| First | Record attacks per month for 4 weeks |
| Then | Follow the label of whatever form you buy |
| Duration | At least 16 weeks before judging |
| Measure | Frequency, not severity or nausea |
| Stop | If nothing has changed by then |
The tea and fresh-leaf versions are covered in tea and leaf preparations, and neither has trial evidence.
- Our label: 1 capsule daily of 1000 mg herb.
- Bottle life: 2 months at that rate.
- Trial protocol: 6.25 mg of extract, 3 times daily.
Whatever the form, the pooled effect on attack frequency across 9 trials in 899 people was a reduction of 1.11, and pain severity did not reach significance.[3]Systematic review and meta-analysis of Tanacetum parthenium: evaluating its efficacy in migraine relief — Natural Product Research (2025) View source That is what our single-herb capsule is buying, stated without dressing it up.
Seek Urgent Assessment Rather Than Adjusting a Dose If
- A sudden severe headache unlike any before, or a headache with fever, neck stiffness, confusion, weakness, vision loss or after a head injury
- Any change in the pattern, frequency or character of long-standing migraines
- Pregnancy, or planning a pregnancy
- Taking warfarin, another anticoagulant, or an antiplatelet medicine
- A known allergy to ragweed, chrysanthemums, marigolds or daisies
Frequently Asked Questions
How much feverfew should I take for migraines? +
The positive trial used 6.25 mg of a standardised CO2 extract 3 times daily. Our capsule is 1000 mg of dried herb, which is a different preparation.
What is the best form of feverfew for migraines? +
The form with the strongest single trial behind it is a standardised CO2 extract. Cochrane could not pool its 6 trials partly because forms varied.
Is 1000 mg too much? +
It is not comparable to the 18.75 mg of extract used in the trial. Bigger is not stronger when the 2 preparations differ.
Should I look for a parthenolide percentage? +
It shows a manufacturer measured something. It is 1 marker rather than a proven active ingredient.
How long before I judge it? +
At least 16 weeks, which is what the trial used after a 4-week baseline.
Should I take it once or 3 times a day? +
The trial split its extract dose across 3 daily doses. Herb capsules are usually labelled once daily, and no trial compared the 2 schedules.
Does feverfew tea work as well? +
There are 0 trials of feverfew tea for migraine prevention. Every positive result here came from capsules or extracts.
With or without food? +
Not 1 trial specified this. Taking it with food is sensible if it upsets your stomach, as with most herb capsules.
Can I take 2 capsules? +
There is no evidence that doubling dried herb helps, since the 1 successful trial used a concentrated extract instead.
How long does 1 bottle last? +
Sixty capsules is 2 months at 1 daily, which covers half of the 16-week trial period.
Do I need to record anything? +
Yes. A 0.6-attack difference cannot be judged without knowing your baseline, which is why the trial recorded for 4 weeks first.
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