L-Theanine During Pregnancy: Is It Safe?

In this article, we will take a close look at L-Theanine, a nonproteinogenic amino acid found in green tea leaves and mushrooms. We will discuss its health benefits, its potential effects on brain chemistry, and if it is safe to consume during pregnancy. Additionally, we will delve into the importance of other essential supplements during pregnancy.
Natasha Puttick

Natasha Puttick

Graduate medical student at Barts and London.

A blue image with text saying "The Health Benefits and Safety of L-Theanine During Pregnancy"

What is L-Theanine?

L-Theanine is a nonproteinogenic amino acid that is primarily found in green tea leaves and some mushrooms. It is one of the umami components of green tea, contributing to its unique flavor [1]. L-Theanine is known for its various health benefits, which has led to its commercial development as a valuable ingredient for various applications in the food and pharmaceutical industries [1]. It can also be found in the form of L-Theanine gummies.

L-Theanine exhibits strong antioxidant-like properties and contributes to the favorable umami taste sensation. Several studies have reported that the consumption of this amino acid has many therapeutic effects, including improvements in brain and gastrointestinal function, cancer drug therapeutic efficacies, antihypertensive effects, and improved immune function [2].

L-Theanine has been historically reported as a relaxing agent, prompting scientific research on its pharmacology. Animal neurochemistry studies suggest that L-Theanine increases brain serotonin, dopamine, GABA levels and has micromolar affinities for AMPA, Kainate and NMDA receptors [3].

Can you take L-Theanine during pregnancy?

There may not be sufficient evidence to answer exactly whether it is safe to take L-theanine during pregnancy. However, it's important to note that L-theanine is an amino acid found primarily in green and black tea, and it's generally considered safe to consume in these forms [4].



Despite this, caution is advised for pregnant women or those breastfeeding when it comes to consuming large amounts of green tea, which contains L-theanine. This is due to the caffeine content, which could potentially lead to issues such as nausea, upset stomach, and irritability [4].


As with any supplement, it's always best to consult with a healthcare provider before starting to take L-theanine, especially for pregnant women or those planning to become pregnant. This is to ensure the safety of both the mother and the baby [4].

What supplements should you take during pregnancy?

During pregnancy, the body's nutritional needs increase, and it's often challenging to meet these requirements through diet alone. As a result, certain supplements are recommended to ensure both the mother and baby's health.

Folic Acid

Folic acid, a B vitamin, is crucial during pregnancy as it may help prevent certain birth defects. The recommended daily intake is 600 mcg from foods or vitamins during pregnancy [5].


Iron is essential for the baby's growth and brain development. Pregnant women are advised to get 27 mg of iron a day [5].


Calcium can reduce the risk of preeclampsia, a serious medical condition that causes a sudden increase in blood pressure. Pregnant adults should get 1,000 mg of calcium a day [5].

Vitamin D

Vitamin D helps the calcium to build up the baby's bones and teeth. All women, pregnant or not, should be getting 600 IU of vitamin D per day [5].


Choline is a vital nutrient during pregnancy and plays an important role in the baby’s brain development. Research suggests up to 95% of pregnant people don’t consume enough choline [6].

Omega-3 Fatty Acids

Omega-3 fatty acids are important for fetal brain development. Some prenatals contain them, but most don't. Most pregnant people take a separate DHA and EPA supplement, like a fish oil or algal oil supplement [6].

Vitamins A and C

Vitamin A is necessary for fetal eye and organ development, immune system function, and more. Vitamin C is necessary for both your health and your baby’s health, and maintaining optimal levels could help reduce your risk of complications such as preeclampsia and preterm birth [6].

B Vitamins

Your body needs eight different B vitamins. During pregnancy, your needs for these nutrients increase. Most prenatal supplements include all eight B vitamins, but some include only a few. At a minimum, a prenatal should include B12, folate, and B6 [6].


While these supplements can be beneficial, it's important to consult with a healthcare provider before starting any new supplement regimen during pregnancy. This is because taking too much of a supplement can be harmful, and each individual's needs may vary [7, 8, 9].

Related Posts

Natasha Puttick

Natasha Puttick

Natasha is a medical student at Barts and the London school of Medicine and Dentistry, with an interest in the social determinants of health. She graduated from the University of Oxford with a BA in Human Sciences and has obtained two publications. Her most recent work investigating clinical vaccine trials has been published in BMJ Public Health.