The drug Topamax (topiramate), which is approved for epilepsy, also can prevent migraines and reduce the need for "emergency" pain medication, according to a study published in the Journal of the American Medical Association. And unlike some other migraine-prevention drugs, including Depakote (valproic acid) and tricyclic anti-depressants such as Elavil (amitriptyline) and Pamelor (nortriptyline), it doesn't cause weight gain. "Topiramate can reduce the number and severity of migraine headaches," says lead author Jan Lewis Brandes, M.D., a neurologist in Nashville, Tenn. "However, it will not replace the medications taken to stop or abort [aheadache]."

Lewis tracked 468 patients, mostly women, who'd had chronic migraines for at least six months. People who took 100 milligrams a day of Topamax reported their migraines dropped from an average of nearly six per month to 3.5; those who took 200 milligrams a day suffered three migraines a month compared with five. Side effects include fatigue and nausea, but also weight loss: Subjects who took Topamax lost 3-4 percent of their body weight, while people on other migraine-prevention drugs sometimes gain as many as 40 pounds.