L-theanine is a naturally occurring compound that’s often used as a supplement to help manage stress and anxiety, improve focus, and support sleep quality.
L-theanine
*image for illustrative purpose only
L-theanine
*image for illustrative purpose only
L-theanine is a naturally occurring amino acid primarily found in green and black tea that’s known for its calming effects on the brain. It is often used as an oral supplement to reduce stress or anxiety and promote relaxation without causing drowsiness.
L-theanine is thought to work by increasing levels of neurotransmitters such as gamma-aminobutyric acid (GABA), serotonin, and dopamine, which help regulate mood and improve cognitive function. Many women take l-theanine to manage stress, improve focus, and support better sleep quality, particularly during timeframes marked by hormonal fluctuations such as premenstrual syndrome or menopause.
While the United States Food and Drug Administration hasn’t approved it for medical treatment, studies suggest l-theanine may also aid in blood pressure regulation and enhance the body's ability to manage stress-related cortisol levels.
Overall, l-theanine is a well-tolerated option for stress relief and cognitive support, but it should be used cautiously in combination with other medications or supplements. Make sure to talk to your healthcare provider before starting any supplements.
L-theanine is not approved as a drug in the United States. It is sometimes taken to improve sleep and reduce anxiety, but research is limited on its true effects
L-theanine is not a drug; it is an amino acid commonly found in teas and certain mushrooms
Information about the potential side effects of l-theanine is limited
The cost of l-theanine may vary depending on the quantity, brand, and where you buy it. Online prices for l-theanine range from about $16 to $60 for a two-month supply of 200-milligram (mg) capsules.
Information about l-theanine is limited
Talk with your healthcare provider if you’re taking medications that help you sleep such as lorazepam, diazepam, or zolpidem. Taking these medications and L-theanine may increase drowsiness
Information about l-theanine is limited
Pregnancy/Breastfeeding: Talk with your healthcare provider if you’re pregnant or breastfeeding. L-theanine may not be safe for you
More research needs to be done on l-theanine for anxiety before we can say for sure that it’s effective. Still, there is some promising evidence in this area. In addition to an abundance of positive anecdotal reports, a systematic review of five randomized controlled trials concluded that l-theanine was linked to significant improvements in stress and anxiety levels in four of the studies.
There is no established dosage of l-theanine for anxiety, but studies have looked at the effects of 200 mg of l-theanine daily for this purpose, which is why many l-theanine supplements are sold in this amount.
No, most research suggests that l-theanine lowers cortisol levels.
*Information about l-theanine is limited. This information was taken, in part, from Memorial Sloan Kettering Cancer Center's website on L-theanine.
This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.
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