This sheet talks about using St. John’s Wort in a pregnancy and while breastfeeding. This information should not take the place of medical care and advice from your healthcare provider.

What is St. John’s Wort?

St. John’s Wort is a flowering plant that is used as an herbal supplement. It is most commonly used to help mild or moderate depression. It is available as a tablet or capsule, liquid extract, tea, and as a cream or ointment, sometimes along with other herbal ingredients.

There are many compounds in St. John’s Wort. The amount and quality of these compounds can vary widely and be affected by the soil the plant is grown in, the harvesting, drying, and how the plant is stored. St. John’s Wort can interact with many different medications. If you are taking any medications, it is very important to talk to your healthcare provider to review the chance of interactions between your medications and St. John’s Wort.

In the United States St. John’s Wort is considered to be a dietary supplement. Unlike a prescription medication, it is not regulated by the Food and Drug Administration (FDA) and does not have set standards for preparation, safety, or effectiveness. For information on supplements in general, please see our fact sheet on herbal products at https://mothertobaby.org/fact-sheets/herbal-products-pregnancy/pdf/.

I take St. John’s Wort. Can it make it harder for me to become pregnant?

There are no studies looking at whether St John’s Wort makes it harder for women to become pregnant.

I just found out that I am pregnant, should I stop taking St. John’s Wort?

Talk with your healthcare providers before making any changes to this supplement. It is important to make sure your condition is well-treated during pregnancy. In some cases for a woman who is very depressed, her healthcare provider may recommend an antidepressant that has been better studied in pregnant women. For more information on depression, please see our fact sheet at https://mothertobaby.org/fact-sheets/depression-pregnancy/.

Does taking St John’s Wort increase the chance for miscarriage?

Miscarriage can occur in any pregnancy. There are no studies looking at the chance of miscarriage and St. John’s Wort.

Does taking St. John’s Wort in the first trimester increase the chance of birth defects?

In every pregnancy, a woman starts with a 3-5% chance of having a baby with a birth defect. This is called her background risk. Two small studies that looked at pregnancies with at least first trimester use of St. John’s Wort did not find an increase in birth defects above the background risk compared to women taking prescription antidepressant medication. However, the number of pregnancies studied was too low to be able to know if St. John’s Wort increases the chance for birth defects.

Could taking St. John’s Wort in the second or third trimester cause other pregnancy complications?

There is little information on the use of St. John’s Wort and possible pregnancy complications. A study that included 39 women who reported using St. John’s Wort early in their pregnancy did not find a higher chance for preterm delivery (delivery before 37 weeks of pregnancy) or poor growth in the babies. There is one report of a woman who started taking St. John’s Wort at week 24 of her pregnancy and had a normal delivery. The woman developed thrombocytopenia, a condition when your blood does not have enough blood cells that help your blood to clot (platelets). Some reports suggest that St. John’s Wort can affect how a person’s blood clots. It is not known if the low platelet count was related to St. John’s Wort or another factor.

Does taking St. John’s Wort in pregnancy cause long-term problems in behavior or learning for the baby?

Studies have not been done to see if St. John’s Wort could increase the chance for long-term problems in behavior or learning for the baby.

Can I breastfeed while taking St. John’s Wort?

In a small study of five breastfeeding mothers of full-term older infants (10-22 weeks), the amount of St. John’s Wort that the infants received through breast milk was found to be small. The mothers reported no negative effects in their infants. Another study, looking at 33 women who took St. John’s Wort and breastfed, reported colic and drowsiness when compared to a group of infants whose mothers had depression but were not taking St John’s Wort. The infants did not need medical treatment.

St. John’s Wort is a long-acting supplement, and any amount ingested by the infant would be expected to remain in their body for a long time. Talk with your healthcare provider about how to best treat your condition while breastfeeding and about all of your breastfeeding questions.

If a man takes St. John’s Wort, could it affect his fertility (ability to get partner pregnant) or increase the chance of birth defects? 

Effects on a man’s fertility from taking St. John’s Wort have not been well-studied. One study found that large amounts of St. John’s Wort added directly to semen reduced sperm movement (motility) and survival. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/pdf/.

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