What feverfew is: A common flower (Tanacetum parthenium) sometimes called a “summer daisy,” feverfew has been used as a medicinal plant since medicine began.
Claims, purported benefits: Treats and/or prevents headaches, arthritis, menstrual irregularity, and fever. Health Canada (the equivalent of the U.S. Food and Drug Administration, or FDA) recognizes feverfew as a nonprescription drug for preventing migraines and reducing the nausea and vomiting that sometimes accompany them.
What the studies show: Animal studies have shown that feverfew may reduce inflammation as well as levels of the hormone-like substances known as prostaglandins; among other effects, some prostaglandins play a role in producing pain sensations and migraine. Since feverfew’s actions seem to resemble those of aspirin, it might also prove useful in treating arthritis.
Research on feverfew as a migraine preventive has yielded confusing results. A few small studies have shown that the leaf of the plant can prevent (not relieve) migraines, meaning that you’d have to take it all the time. The jury is still out. There is little or no research on other possible benefits.
No one is sure which compound in the plant may have medicinal effects. In Canada, standardized doses of dried leaves are sold over the counter, but in the United States, commercially available preparations may have very little plant material in them. If you have feverfew in your garden—and are certain that’s what it is—you could try the fresh leaves: Two or three leaves a day taken with food is the dosage recommended by herb experts. An infusion (that is, tea) is another way to take feverfew.
Side effects: Mouth ulcers, stomach irritation and nausea. Feverfew may interact with aspirin, so if you take aspirin or any other anti-inflammatory drug regularly, talk with your doctor before taking it. If you are allergic to chamomile, ragweed or yarrow— or if feverfew gives you a rash—don’t swallow it. If you take it and then discontinue its use, you may get rebound headaches. The long-term effects are unknown. Children and pregnant or nursing women should not take feverfew.
Bottom line: Though studies of feverfew for preventing migraines have yielded confusing results, people suffering from migraines might want to try it. It’s not expensive and has helped in some studies.