There isn't a clear optimal dose of feverfew for any condition. Quality and active ingredients in supplements may vary widely from maker to maker. This makes it hard to set a standard dose.
Can you get feverfew naturally from foods?
Some people eat the feverfew leaves, but they are bitter and may hurt your mouth.
What are the risks of taking feverfew?
Side effects. People have not reported serious side effects of feverfew. Researchers have used it safely with people in studies lasting up to four months. No one knows whether it is safe if you use it longer than that.
Side effects may include symptoms affecting the mouth, such as:
Loss of taste
Swollen, irritated lips and tongue
These side effects may be more common if you chew on feverfew leaves.
Some people have other side effects if they stop taking feverfew suddenly after long-term use. These include:
It is also possible to have allergic reactions to feverfew. This is more likely if you have an allergy to plants in the daisy family, such as ragweed.
Risks. Do not take feverfew if you are pregnant. Feverfew may cause your uterus to contract. This may raise the risk of miscarriage or preterm delivery. It's also best to avoid using it when breastfeeding.
Interactions. It is possible that feverfew may affect blood clotting, but this has not been proven in humans. Just to be safe, it may be best to avoid combining feverfew with other blood-thinning supplements or drugs. These include:
Stop using feverfew at least two weeks before surgery to lessen the risk of bleeding.
Feverfew may also interact with drugs that are changed by the liver, such as lovastatin or fexofenadine and many others. Don't take feverfew unless your doctor says it is OK.
The FDA does not regulate supplements. Be sure to tell your doctor about any you're taking, even if they're natural. That way, your doctor can check on any potential side effects or interactions with medications or foods. He or she can let you know if the supplement might raise your risks.