Migraine Prevention and Maintenance: 25 - 75 mg of Feverfew , taken two to three times per day.
To Abort a Migraine Attack: 1,000 - 2,000 mg may be necessary at the onset of an acute attack.
Arthritis: Clinical trials have used a daily dosage of 76 mg of Feverfew.
Based upon some evidence, using a standardized grade containing capsules or tablets with a parthenolide concentration of 0.4 to 0.7 % may be a consideration. As such, the daily dosage of parthenolide should yield at least 250 mcg.
Adverse Side Effects, Toxicity and Contraindications
Among the many thousands of English citizens who commonly use Feverfew for the above stated medicinal purposes, there have been no reports of serious toxicity, which is also supported by animal experiments. 12 At recommended levels of intake Feverfew extract may produce minor side effects, such as gastrointestinal upset and nervousness in a small percentage of patients.
Parthenolide exhibits anti-platelet clotting properties and can potentially lead to a bleeding disorder in patients with a history of capillary or vascular fragility. As such, it should be use with caution in these individuals.
Chewing the leaves of the Feverfew plant may result in apthous ulcerations or exudative dermatitis from external contact, in sensitive individuals.
Anticoagulant Medications (e.g., coumadin, warfarin) - Feverfew may potentiate the anti-clotting effects of these drugs, increasing the risk of a bleeding disorder. Thus, appropriate patient monitoring of prothrombin time (INR) must accompany the concurrent use of Feverfew and anti-coagulant medications.