Is St. john's wort safe during pregnancy?

What does the evidence say about St. john's wort during pregnancy?

1. Three earlier studies of St. John's wort in pregnancy didn't find an increase in birth defects, and one found a similar miscarriage rate to the general population, though the herb still hasn't been well studied in pregnancy overall. 1
2. NCCIH states it may be unsafe to use St. John's wort during pregnancy because it may increase the risk of birth defects, and that breastfeeding infants of mothers who take it can experience colic, drowsiness, and lethargy. 2
3. St. John's wort can weaken how well other important medications work, including birth control pills, some antidepressants, and the blood thinner warfarin, and combining it with certain antidepressants can raise the risk of serious serotonin-related side effects. 2
4. A clinical review for physicians concludes that St. John's wort cannot be recommended as safe therapy during pregnancy, noting there are almost no data on its reproductive safety. 3
5. In lactation research, infants of mothers taking St. John's wort received on average about 1.5% of the mother's weight-adjusted dose through breastmilk, and while affected infants didn't need medical care, reviewers suggest an alternate medication may be preferred for a newborn or preterm infant. 4

Is St. john's wort safe in each trimester?

• First trimester. Most of the reported birth-defect signal in claims-data research traces back to first-trimester exposure, which is when any risk to development would matter most. This is also when untreated depression carries its own real risks, so stopping or starting St. John's wort is a conversation to have with your provider rather than a decision to make alone.
• Second trimester. Data specific to the second trimester is limited. The bigger practical issue at any point in pregnancy is that St. John's wort can weaken how well other medications work, including birth control and some antidepressants, so any other prescriptions need to be reviewed alongside it.
• Third trimester. A case report has linked St. John's wort to low platelet counts, which could matter around delivery. If you're taking it near your due date or plan to breastfeed afterward, ask your provider about the safest way to continue or stop, since it also passes into breastmilk.