Does it work?
Feverfew is often taken by mouth for migraine headache prevention. Laboratory studies show that feverfew may reduce inflammation and prevent blood vessel constriction (squeezing) that may lead to headaches. Most of the available human studies are not high quality and report mixed results. However, overall they do suggest that feverfew may reduce the number of headaches that occur in people with frequent migraines.
Dangers and natural alternatives....
Avoid if allergic to feverfew and other plants of the Compositae family (chrysanthemums, daisies, marigolds, ragweed). Stop use prior to surgery and dental or diagnostic procedures. Avoid with drugs that increase bleeding risk. Avoid stopping feverfew use all at once. Instead, slowly take less and less over several days. Avoid with history of heart disease, anxiety or bleeding disorders. Caution is advised with history of mental illness, depression and headaches. Avoid if pregnant or breastfeeding.