Feverfew is primarily used to prevent migraines. This flowering plant, a member of the daisy family, has been a folk remedy for centuries, applied to everything from fevers and toothaches to arthritis and menstrual problems. But migraine prevention is the use with the most clinical attention, and it’s the reason most people encounter feverfew today.
How Feverfew Works in the Body
The key active compound in feverfew is parthenolide, a substance found in the plant’s leaves and flowers. Parthenolide works through several pathways at once. It blocks the release of serotonin from platelets and reduces serotonin release from nerve cells. Since serotonin fluctuations play a central role in triggering migraines, this is thought to be the main reason feverfew helps some migraine sufferers.
Parthenolide also suppresses the production of inflammatory prostaglandins, compounds your body makes that drive pain and swelling. It does this by binding to and inhibiting a protein complex called IKKβ, which acts as a switch for inflammatory signaling. This anti-inflammatory action is why feverfew has historically been tried for conditions like arthritis, though the evidence there is much weaker. Additionally, parthenolide interacts with pain-sensing receptors in the nerve system that supplies the head and face, which may help reduce the pain signaling and blood vessel dilation that occur during a migraine.
Migraine Prevention: What the Evidence Shows
The most studied use of feverfew is preventing migraines, not treating them once they start. A Cochrane review, the gold standard for evaluating clinical evidence, found that feverfew reduced migraine frequency by about 0.6 attacks per month compared to placebo. In one of the larger trials (170 participants), people taking a standardized feverfew extract went from an average of 4.8 migraines per month down to 2.9, while the placebo group dropped only to 3.5.
That said, the evidence is mixed. Three smaller trials (ranging from 17 to 60 participants) found positive effects, but two more rigorous trials with larger groups did not find significant differences between feverfew and placebo. The Cochrane review also found no meaningful benefit for migraine intensity, duration, or the nausea and vomiting that accompany attacks. So while some people clearly respond to feverfew, the overall picture is one of modest benefit with inconsistent results across studies.
The formulation matters. Earlier positive trials used powdered, freeze-dried feverfew leaves, while some of the trials showing no benefit used CO2 extracts. In one early crossover study, participants who switched from feverfew to placebo saw their migraine frequency jump significantly, while those staying on feverfew held steady at about 1.7 attacks per month. That same study found noticeably less nausea and vomiting in the feverfew group. These differences between formulations make it difficult to draw firm conclusions about feverfew as a whole.
Other Traditional Uses
Feverfew has a long history of use for a wide range of complaints: fever (as the name suggests), stomach aches, toothaches, insect bites, menstrual irregularities, allergies, asthma, tinnitus, dizziness, and skin conditions like psoriasis and dermatitis. These uses come from folk medicine traditions rather than clinical trials.
One use that has been formally tested is rheumatoid arthritis. A double-blind, placebo-controlled trial gave 41 women with rheumatoid arthritis either feverfew or placebo capsules daily for six weeks. The result was clear: no meaningful difference between the two groups on any clinical or laboratory measure. Despite feverfew’s demonstrated anti-inflammatory properties in lab settings, those effects have not translated into measurable benefits for arthritis in humans.
Dosage and Product Variability
One of the biggest practical challenges with feverfew is that products on the market vary enormously. A study analyzing commercially available feverfew supplements found a 10-fold variation in the amount of dried leaf per daily dose (225 to 2,246 mg) and a staggering 160-fold variation in parthenolide content (0.06 to 9.7 mg per day). The percentage of parthenolide in each product ranged from 0.14% to 0.74%.
This means two different feverfew products from two different brands may deliver wildly different amounts of the compound that actually matters. If you’re choosing a feverfew supplement, look for one that lists a standardized parthenolide content on the label. Many of the clinical trials used preparations standardized to a specific parthenolide percentage, and without that standardization, there’s no reliable way to know what you’re getting.
Forms of Feverfew
Feverfew comes in several forms: fresh leaves, powdered dried leaves in capsules, alcohol-based extracts, and CO2 extracts. Chewing fresh leaves is the oldest method, but it comes with a notable downside. Fresh leaves can cause sores and irritation inside the mouth. Dried leaf capsules avoid this problem and were the form used in several of the trials that showed positive migraine results. Standardized extracts offer the most consistent parthenolide content but, as noted above, haven’t always performed well in trials. For most people, capsules containing powdered or freeze-dried leaves are the most practical option.
Side Effects and Safety Concerns
Feverfew is generally well tolerated. The most common side effects are nausea, digestive discomfort, and bloating. Mouth sores are specific to chewing fresh leaves and don’t typically occur with capsules.
The more important safety concern involves bleeding. Feverfew can slow blood clotting, so it should be stopped at least two weeks before any scheduled surgery. For the same reason, people taking blood-thinning medications should be cautious about combining them with feverfew.
There’s also a withdrawal phenomenon sometimes called “post-feverfew syndrome.” People who stop taking feverfew abruptly after long-term use can experience a rebound in migraine frequency, along with anxiety, poor sleep, and muscle stiffness. If you’ve been taking feverfew regularly and want to stop, tapering off gradually is a better approach than quitting all at once.