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L-theanine
Also called: Theanine, Suntheanine
A calming amino acid from tea leaves. It may ease stress and support relaxed focus without making you drowsy.
Commonly used for
- Stress and a busy mind
- Calm focus
- Sleep quality
- Smoothing out coffee jitters
Found naturally in
- Green tea
- Matcha
- Black tea
- White and oolong tea
Label red flags
- Lists 'theanine' without specifying the L-form
- Calming blends that combine many sedating herbs
Check with a provider
- Pregnancy or breastfeeding (not well studied)
- Taking blood pressure medicines, since it may lower blood pressure slightly
- Taking sedatives or sleep medicines
Supplements that contain it
Brand nameProduct nameStress and calm formulasComing soon
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Brand nameProduct nameFocus formulasComing soon
Brand nameProduct nameStress and calm formulasComing soon
Brand nameProduct nameSleep formulasComing soon
Brand nameProduct nameFocus formulasComing soon
Parts of the body it affects
Explore what each area does and the conditions that can affect it.
Illustrations: Servier Medical Art, CC BY 4.0

Wondering if your symptoms fit a pattern?
Dr. Lesher is a naturopathic doctor who specializes in women's autoimmune and chronic conditions. Since 2020, she has helped more than 900 patients overcome and heal from their conditions.
