Is L-Theanine Safe While Pregnant?

Many expectant mothers question the safety of nonherbal teas and dietary supplements during pregnancy. L-theanine is a chemical compound extracted from tea leaves known for its antioxidant properties and relaxing effects. Pregnant women should avoid L-theanine due to insufficient research regarding the safety of the compound on fetal development. Always consult your physician before ingesting any type of herbal supplement or tea during pregnancy.

Avoid L-theanine supplements during pregnancy. (Image: Umkehrer/iStock/Getty Images)


L-theanine, an amino acid derived from tea leaves and Boletus badius mushroom, is absorbed by the small intestine and crosses the blood-brain barrier. The amino acid is structurally related to glutamic acid, a neurotransmitter in the brain, and increases dopamine levels in the brain. While L-theanine is present in most varieties of tea, the oxidation of black tea destroys the presence of the amino acid. L-theanine is also available as a dietary supplement in health food stores.

Potential Benefits

Naturally present in green and white tea, L-theanine, when paired with caffeine, reportedly increases alertness and improves cognitive function. According to research published in February 2008 in the journal "Biological Psychology," beverages containing a combination of L-theanine and caffeine improved cognitive function and alertness in participants more than beverages containing only caffeine. L-theanine may aid in stress relief by producing a relaxing effect, and it may play a role in preventing certain cancers. More research is necessary to test the validity of these claims. There are no benefits of L-theanine directly related to pregnancy.

Nonherbal Teas and Pregnancy

Nonherbal teas, including green and oolong, contain both L-theanine and caffeine. Even decaffeinated versions of nonherbal teas contain traces of caffeine. Although nonherbal teas provide various health benefits, the caffeine content may be unsafe during pregnancy. Caffeine crosses the placenta and may effect the development of your unborn baby. Consult your obstetrician or midwife about the safety of caffeine before drinking nonherbal teas during pregnancy.


Adverse side effects may occur as a result of ingesting tea extracts or dietary supplements. These side effects include gastrointestinal problems, headache and dizziness. Expectant mothers should avoid L-theanine during pregnancy due to a lack of scientific research regarding the safety and efficacy of the compound. Always consult your physician before using any type of dietary supplement during pregnancy.

Load Comments

Copyright © 2019 Leaf Group Ltd. Use of this web site constitutes acceptance of the LIVESTRONG.COM Terms of Use , Privacy Policy and Copyright Policy . The material appearing on LIVESTRONG.COM is for educational use only. It should not be used as a substitute for professional medical advice, diagnosis or treatment. LIVESTRONG is a registered trademark of the LIVESTRONG Foundation. The LIVESTRONG Foundation and LIVESTRONG.COM do not endorse any of the products or services that are advertised on the web site. Moreover, we do not select every advertiser or advertisement that appears on the web site-many of the advertisements are served by third party advertising companies.