Feverfew

EVIDENCE: MIXED

Also sold as: Tanacetum parthenium, parthenolide, bachelor's buttons, featherfew

Feverfew has randomized research for migraine prevention, including standardized extracts. Results are mixed, and Cochrane judged the overall evidence uncertain. The amount of parthenolide, one of its key compounds, matters when comparing products with studies.

Compiled by iSupplementReviews editorial team ·Updated 2026-10-06 · 4 sources

Type: Botanical (migraine herb)
Studied dose: 100–143 mg/day of a parthenolide-standardized extract (MIG-99); leaf ~50–100 mg/day
Best form: Parthenolide-standardized extract (≥0.2% parthenolide) — the trials' material
Upper limit: No established upper intake limit — oral ulcers and 'post-feverfew syndrome' (rebound headache) are the known adverse pattern
Our rating: MIXED — Some human evidence, inconsistent or indirect

What is feverfew?

Feverfew (Tanacetum parthenium) is a daisy-family herb traditionally used for headache. Parthenolide has proposed effects on platelet serotonin release and inflammatory signaling. Randomized migraine trials have produced mixed, modest results.

What does the research show?

Claim	Evidence	Dose studied	Verdict
Migraine prevention	4 trials + Cochrane review	50–143 mg/day (standardized)	Mixed-positive — modest effect
Anti-inflammatory	Lab work + the migraine trials	—	Mechanism established
‘Detox’/liver claims	No supporting human data	—	Unproven
Oral/dental benefit	No data	—	Unproven

The migraine file deserves precision: the 1980s trials were small and positive; the largest standardized trial (MIG-99, n=170) reduced frequency ~0.5 attacks/month vs placebo, statistically real, clinically modest. Cochrane’s verdict across the trials: benefit exists but is small and inconsistent. Good enough to keep it off the ‘pure folklore’ shelf, nowhere near enough to call proven.

What dose was studied?

Goal	Dose	Form
Migraine prevention	~50–143 mg/day (≥0.2% parthenolide)	standardized extract or dried leaf, months

Side effects

Mouth ulcers on fresh-leaf contact, digestive upset. The signature phenomenon: post-feverfew syndrome, rebound headaches, anxiety, insomnia, stiffness after stopping long-term use. Not dangerous, but documented.

Drug interactions

Blood thinners: parthenolide inhibits platelet aggregation; additive with warfarin/aspirin is the meaningful caution.
NSAIDs: theoretically may blunt the migraine benefit itself (the herb works partly via serotonin release).

Who should not take it

Pregnant women (uterine-stimulant tradition), daisy-family allergy, people on anticoagulation, and, uniquely, anyone who’s been on it long-term and stops abruptly.

What the authorities say

Cochrane: low-moderate certainty of a small preventive effect. MSKCC: effective for some in migraine prevention, insufficient data for anything else. Regulatory endorsement has not been established.

What to know about feverfew

Feverfew’s research concerns migraine prevention, not dental benefits. Check the standardized preparation and parthenolide content when comparing products with trials. Its interaction and pregnancy cautions remain relevant even in a mixed formula.

Frequently asked questions about Feverfew

Does feverfew prevent migraines?

The fairest summary is 'probably a little, inconsistently.' The early trials were positive (Johnson 1985 n=17 crossover; Murphy 1988 n=72, frequency and severity dropped); the big standardized trial (Pfaffenrath 2002, n=170, MIG-99) cut migraine frequency by about half an attack per month vs placebo; and the Cochrane update calls the overall evidence mixed-to-modest. It's real, it's small, and it's the best human file most blend-mates will never have.

What is parthenolide and why does the label need it?

Parthenolide is feverfew's active compound, the one the trials standardized for (≥0.2%). Leaf powder without standardization varies wildly; some commercial products have tested at near-zero parthenolide. 'Feverfew' without a parthenolide percentage is a coin toss.

Why is feverfew in a dental supplement?

Human research has not established a dental benefit. Feverfew has been studied mainly for migraine prevention. Its effects on inflammation in laboratory research do not demonstrate that it improves teeth or gums.

Is feverfew safe?

For most, at studied doses. But it has a signature quirk: mouth ulcers from chewing fresh leaves (direct contact irritation), and 'post-feverfew syndrome,' rebound headaches, insomnia, muscle aches after abruptly stopping long-term use. Ragweed-family allergy applies.

Who shouldn't take feverfew?

Pregnant women (traditional uterine-stimulant caution, real), people on blood thinners (platelet activity, real), daisy-family allergy, and anyone already on migraine preventives without telling their clinician.