Butterbur in pregnancy and breastfeeding

What NCCIH says about safety

The butterbur plant contains substances called pyrrolizidine alkaloids (PAs). PAs can damage the liver and lungs and may cause cancer. Only butterbur products that have been processed to remove PAs and are labeled or certified as PA-free should be considered for use. Several studies, including studies of children and adolescents, have reported that PA-free butterbur products seem to be safe when taken by mouth for up to 16 weeks. However, there have been rare cases of liver injury associated with products that were reported to be PA-free. Butterbur products that contain PAs may not be safe when applied to the skin. PAs could be absorbed through cuts or scrapes. Butterbur is generally well tolerated when taken orally. Side effects can include belching, diarrhea, drowsiness, rash, and stomach upset. Butterbur may cause an allergic reaction in people who are allergic to related plants, such as ragweed, chrysanthemums, marigolds, and daisies. If you take any type of medicine, talk with your health care provider before using butterbur or other herbal products; some herbs and medicines interact in harmful ways. Butterbur products with PAs should not be used during pregnancy or while breastfeeding because they may cause birth defects or liver damage. Little is known about whether it’s safe to use PA-free butterbur products during pregnancy or while breastfeeding.

Quoted in full from NCCIH so nothing is lost in summarising. Where they say “little is known”, that means the studies do not exist — not that the herb is known to be safe, and not that it is known to be harmful.

How much is actually known

There have been several studies of butterbur for migraines and allergic rhinitis (hay fever) in people, so we have some knowledge of its effects on these two conditions.

What the research has found

A butterbur root extract may reduce the frequency of migraines in adults and children when taken orally. In 2012, the American Academy of Neurology recommended butterbur for preventing migraines. However, the Academy stopped recommending it in 2015 because of serious concerns about its safety. Studies of a butterbur leaf extract suggest that it may be helpful for symptoms of allergic rhinitis when taken orally. Little research has been done on butterbur for conditions other than migraine and allergic rhinitis, and no conclusions can be reached about its effects for other conditions.

Before you take this

Dose and form change the answer completely. A culinary amount of a spice, a cup of tea, and a concentrated supplement extract are three different things, and most research is done on the last of them.

Supplements are also not regulated like medicines, so strength and purity vary between products. Bring the actual bottle to your midwife, doctor or pharmacist — that conversation is worth more than any page, including this one.