Feverfew (Tanacetum parthenium L.) (Asteraceae) is a medicinal plant traditionally used for the treatment of fevers, migraine headaches, rheumatoid arthritis, stomach aches, toothache and even insect bites
Feverfew leaves contain many different chemicals, including one called parthenolide.
Parthenolide or other chemicals decrease factors in the body that might cause migraine headaches