Feverfew

Claims, Benefits: Treats headaches, menstrual irregularity, and fever.

Bottom Line: Though studies of feverfew as a migraine preventive have had confusing results, people suffering from migraines might want to try it. Canada's Health Protection Branch recognizes feverfew as a nonprescription drug for preventing migraines. But in Canada, standardized doses of the dried leaves are sold over the counter, while in the U.S., commercially available preparations usually have very little plant material in them. Feverfew may interact adversely with aspirin.

Full Article, Wellness Letter, September 1999:

A daisy for migraines?

A common garden flower (Tanacetum parthenium) sometimes called a "summer daisy," feverfew has been used as a medicinal plant since medicine began—and is one of the most interesting and potentially valuable of herbs. It's been used to treat headaches, menstrual irregularity, and fever. Experiments with animals have shown that it may reduce inflammation as well as the hormone-like substances known as prostaglandins; among other effects, prostaglandins play a role in producing pain sensations and migraine. Feverfew's actions might resemble those of aspirin, and it might therefore prove useful in treating arthritis. But no one is sure which chemical in the plant may have medicinal effects.

Studies of feverfew as a migraine preventive have had confusing results. One or two have shown that the leaf of the plant can prevent (not relieve) migraines, meaning that you'd have to take it all the time. In a recent issue of Cephalalgia researchers in the Department of Complementary Medicine at the University of Exeter in England reviewed the clinical work on feverfew and concluded that the jury was still out. As quoted in a later interview in Lancet, one of these researchers, Dr. Edzard Ernst, doubted that feverfew's active compound had been identified. Still, people suffering from migraines might try it: "It's not expensive, it's not risky, and it has helped in some studies." Convincing evidence may be a long time in coming because drug companies are unlikely to commission research on something they cannot patent.

Canada votes yes

If you want to try feverfew, you may be wasting your money on what you find in the drugstore or health-food store. Dr. Varro Tyler, an American herb expert interested in the potential of feverfew, says that commercially available preparations usually 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 to three leaves daily taken with food is the dose recommended by herb experts. An infusion (that is, tea) is another way to take feverfew. Canada's Health Protection Branch recognizes feverfew as a nonprescription drug for preventing migraines and reducing the nausea and vomiting that sometimes accompanies them. In Canada, standardized doses of dried leaves are sold over the counter.

Side effects may include mouth ulcers, stomach irritation, and nausea. Feverfew may interact with aspirin, so if you take aspirin or any anti-inflammatory drug regularly, talk with your physician before trying feverfew. If you are allergic to chamomile, ragweed, and yarrow—or if feverfew gives you a rash—you should steer clear of swallowing it. There's some evidence that if you take it and then discontinue its use, you can get rebound headaches. No one, of course, knows what its long-term effects might be.

Children and pregnant or nursing women should not take this herb.

UC Berkeley Wellness Letter, September 1999