Is It Safe to Take Herbal Supplements and Teas During Pregnancy?

More than 400 different herbs are commonly used to treat or prevent a variety of conditions. They are sold in many forms, including teas, tablets, capsules and extracts.

Herbal supplements are not necessarily safe to take during pregnancy, however. The safety and effectiveness of herbal supplements have not been studied, especially during pregnancy. The March of Dimes recommends that pregnant women avoid them. The only supplement the March of Dimes does recommend is a multivitamin with at least 400 micrograms of folic acid.

Herbal preparations are classified as dietary supplements by the Food and Drug Administration and are not regulated like conventional drugs. Manufacturers are not required to follow any standard quality controls, nor do they have to perform safety or effectiveness studies before marketing their products. As a result, the quality and strength of an herbal supplement can vary greatly between two batches of the same product and between products from different manufacturers. Some preparations may interact with other medications, potentially making them less active or less safe.

Herbal teas can be soothing, and pregnant women bothered by nausea and vomiting may be tempted to use them. But they should not be taken without the advice of a health care provider. Large amounts of some herbal teas, including peppermint and red raspberry leaf, are thought to cause uterine contractions and may increase the risk of miscarriage or preterm labor. This also is true of many herbal tablets, capsules and extracts, including black or blue cohosh, ephedra, dong quai, feverfew, juniper, pennyroyal, St. John's wort, rosemary and thuja.