What Is Feverfew Used for Today?
| What Is the Scientific Evidence for Feverfew?
| Safety Issues
| Interactions You Should Know About
Originally native to the Balkans, this relative of the common daisy was spread by deliberate planting throughout Europe and the Americas. Feverfew's feathery and aromatic leaves have long been used medicinally to improve childbirth, promote menstruation, induce abortions, relieve rheumatic pain, and treat severe headaches.
Contrary to popular belief, feverfew is not used for lowering fevers. Actually, according to one source, "feverfew" is a corruption of the name "featherfoil."
Featherfoil became featherfew and ultimately feverfew. In a weird historical reversal, this name then led to a widespread belief among herbalists that feverfew could lower fevers. After a while they noticed that it did not work, and then angrily rejected feverfew as a useless herb! Feverfew remained out of fashion until a serendipitous event occurred in the late 1970s.
At that time, the wife of the chief medical officer of the National Coal Board in England suffered from serious migraine headaches. When workers in the industry learned of this fact, a sympathetic miner suggested she try a folk treatment he had used. She followed his advice and chewed feverfew leaves. The results were dramatic: her migraines disappeared almost completely.
Her husband was impressed, too. He used his high office to gain the ear of a physician who specialized in migraine headaches, Dr. E. Stewart Johnson of the London Migraine Clinic. Johnson subsequently experimented with feverfew in his practice and seemed to observe good results. This led to the studies described below.
What Is Feverfew Used for Today?
Feverfew is primarily used for the
. For this purpose, it is taken daily. There has been no formal investigation of feverfew as a
for migraines that have already started, although one double-blind study evaluating feverfew as a preventive agent did find hints of possible symptom-reducing benefits.
It is important to remember that serious diseases may occasionally first present themselves as migraine-type headaches. For this reason, proper medical diagnosis is essential if you suddenly start having migraines without a previous history, or if the pattern of your migraines changes significantly.
Feverfew is sometimes recommended for
, but there is no evidence at all that it works.
What Is the Scientific Evidence for Feverfew?
studies have been performed to evaluate feverfew's effectiveness as a preventive treatment for migraines. The best of the positive trials used a feverfew extract made by extracting the herb with liquid carbon dioxide. Two other trials that used whole feverfew leaf also found it effective; however, two studies that used feverfew extracts did not find benefit.
In a well-conducted 16-week, double-blind, placebo-controlled study of 170 people with migraines, use of a feverfew extract at a dose of 6.25 mg 3 times daily resulted in a significant decrease in headache frequency as compared to the effect of the placebo treatment.
In the treatment group, headache frequency decreased by 1.9 headaches per month, as compared to a reduction of 1.3 headaches per month in the placebo group. The average number of headaches per month prior to treatment was 4.76 headaches. The extract used in this study was made utilizing liquid carbon dioxide.
A previous study using the same extract had failed to find benefit, but it primarily enrolled people with less frequent migraines.
Two other studies used whole feverfew leaf and found benefit. The first followed 59 people for 8 months.
For 4 months, half received a daily capsule of powdered feverfew leaf; the other half took placebo. The groups were then switched and followed for an additional 4 months. Treatment with feverfew produced a 24% reduction in the number of migraines and a significant decrease in nausea and vomiting during the headaches. A subsequent double-blind study of 57 people with migraines found that use of feverfew leaf could decrease the severity of migraine headaches.
Unfortunately, this trial did not report whether there was any change in the frequency of migraines; it is possible, therefore, that this study actually showed a symptom-reducing effect rather than a preventive benefit.
A review of 6 randomized trials, including some of the trials above, did not find benefit of feverfew for preventing migraine headaches.24
One study using an alcohol extract failed to find benefit.
Some migraine sufferers experience a mild headache before the onset of their full blown migraine. A randomized trial involving 60 such patients found that a sublingual (placed under the tongue for rapid absorption) combination of feverfew and
taken at the onset of this early headache helped to reduce or eliminate pain for at least 2 hours.
The tested liquid-carbon-dioxide feverfew extract is taken at a dose of 6.25 mg 3 times daily. To replicate the dosage of feverfew used in the two positive studies of whole leaf described above, take 80 to 100 mg of powdered whole feverfew leaf daily.
Animal studies suggest that feverfew is essentially nontoxic.
In one 8-month study, there were no significant differences in side effects between the treated and control groups.
There were also no changes in measurements on blood tests and urinalysis.
In a survey involving 300 people, 11.3% reported mouth sores from chewing feverfew leaf, occasionally accompanied by general inflammation of tissues in the mouth.
A smaller percentage reported mild gastrointestinal distress.
However, mouth sores do not seem to occur in people who use encapsulated feverfew leaf powder, the usual form.
In view of its use as a folk remedy to promote abortions, feverfew should probably not be taken during pregnancy.
Because feverfew might slightly inhibit the activity of blood-clotting cells known as platelets,
it should not be combined with strong anticoagulants, such as warfarin (Coumadin) or heparin, except on medical advice. Feverfew might also increase the risk of stomach problems if combined with anti-inflammatory drugs, such as aspirin.
Safety in young children, pregnant or nursing women, or those with severe kidney or liver disease has not been established.
Interactions You Should Know About