Each supplement will have a different recommended dose so be careful. Having said that, studies find that taking from 100 - 300 mg of a feverfew supplement containing 0.2 - 0.4% standardized parthenolide 1 to 4 times a day is safe to treat migraine headaches. BUT feverfew is unsuitable for some people and those taking certain medications and has side effects. So check with your doctor before taking this supplement. [4]