Feverfew (Tanacetum parthenium) doesn't do much for fevers, but scientific studies show that it's good news for migraine sufferers. Add two or three fresh, feathery leaves to your sandwich or salad, or infuse them in a tea. (Don't give up if you don't feel immediate relief. Researchers say that consumption for several months yields the best results.) The medicinal plant has slightly more parthenolide--the active constituent that quiets the pain--than ornamental varieties. If possible, buy the plant or seeds from a source which claims a parthenolide concentration of 0.4% or more.