Feverfew consists of the dried aerial parts of dried leaves of Tanacetum parthenium (L.) Schulz. Bip. (syn. Chrysanthemum parthenium [L.] Bernh.) [Fam. Asteraceae], collected when the plant is in flower.
Experts believe the sesquiterpene lactone parthenolide is one of the primary active constituents responsible for feverfew's bioactivity.
Unless otherwise prescribed: Drug equivalent to 0.2mg. to 0.6mg. of parthenolide. Dried aerial parts, 50mg. to 200mg. (normally in tablets or capsules). Tincture (1:5, 25% ethanol), 5 to 20 drops.
Duration of application: At least a few months is recommended. From time to time, a pause in treatment is advisable while gradually reducing the dosage during the preceding month.