While herbal preparations have been used for thousands of years to treat everything from headache to the plague, the advent of formal clinical study on these herbs is relatively recent. As a result, the body of modern scientific literature — in the form of large, controlled, randomized, and long-term trials — is small on most herbal supplements in comparison to the body of literature on commercial prescription and over-the-counter drugs. This is attributable to several factors, including the large amount of research funding provided by pharmaceutical companies, and the differences in regulatory processes between drugs and supplements.

Several herbal supplements have been studied for use in migraine treatment, and the research data, though limited, provides some indication of their efficacy. Those herbs that have the most positive research results in relation to migraine treatment are described below.

Feverfew (Tanacetum parthenium, Chrysanthemum parthenium) is a medicinal herb that has been used to treat various ailments — including headache — for centuries. The feverfew bush, which is also known commonly as bachelor's buttons, is a fast-growing plant that has daisylike flowers when in bloom. The herb is native to Europe but is now widespread throughout North and South America.

While feverfew leaves are sometimes taken medicinally, commercial preparations of the supplement may contain leaves, flowers, and stems processed into capsule, tablet, or liquid extract formulations. Due to variations in plant varieties and manufacturing processes, the strength and quality of feverfew supplements you may find at your local health food store can fluctuate widely (see the Smart Supplementation section that follows).

Studies of feverfew in migraine treatment have had mixed results. The herb may have some benefit as a preventative medication, but as is the case with most supplements for migraine prevention, there have not been enough large-scale, long-term, controlled trials to reach a definitive conclusion on the herb. In addition, several of the existing studies test not feverfew alone but in combination with another substance.

For example, a sublingual (under the tongue) compound of feverfew and ginger was used in one small study to treat head pain at the beginning of a migraine attack, and close to half of the subjects reported no pain two hours after treatment. And another study combined feverfew with the herb white willow (Salix alba) to produce a compound that reduced the frequency, severity, and duration of migraine after three months of daily supplementation.

But some research has determined that feverfew is not any more effective than placebo in managing migraine pain. Clearly, further research is necessary to determine whether feverfew holds promise as a migraine treatment. In the meantime, it may be an option for those who cannot tolerate the side effects of other prescription and over-the-counter medications.

Feverfew has a few potential but uncommon side effects, including nausea, bloating, canker sores, irritation of the lips and tongue, and changes in sense of taste. Sudden withdrawal of the herb after long-term use has also been associated with sleeplessness, headache, anxiety, and muscle pain.

Butterbur (Petasites hybridus), also know as butterfly dock, bog rhubarb, and blatterdock, has been used for medicinal purposes since the fourteenth century. This perennial plant is small with large, rhubarblike leaves and spiky flowers, and has a large rhizome, or root, which is used in herbal preparations.

While butterbur has been studied extensively as a treatment for allergies because of its anti-inflammatory and antihistamine properties, less research exists on its role as a migraine treatment. Most studies involve an extract of the butterbur root taken in tablet form, known commercially as Petadolex. While further long-term, welldesigned studies of the herb are needed, existing studies indicate that butterbur has some efficacy as a migraine preventative.

Like feverfew, butterbur is related to ragweed and can cause an allergic reaction in anyone with an existing ragweed allergy. The herb has not been studied extensively enough to document all potential side effects, but those that have been reported in conjunction with clinical trials include nausea, belching, and other mild digestive complaints.