- What is L-theanine? Often just called theanine, L-theanine, is a water-soluble amino acid found in black and green tea (See What It Is).
- What are the health benefits of L-theanine? Some small clinical studies (funded by manufacturers of L-theanine) have found L-theanine may reduce stress, anxiety and blood pressure in stressful situations, but not all studies have found a benefit (See What It Does).
- How much L-theanine should I take? L-theanine is typically taken at a dose of 200 mg to 400 mg per day (See Dosage).
- L-theanine safety and side effects: At these doses, it appears to be generally safe, but there are possible interactions with blood pressure medications and benzodiazepines (See Concerns and Cautions).
- Best value for L-theanine: ConsumerLab.com did not find problems with the quality of selected L-theanine products sold in the U.S., but did find large differences in the cost to obtain L-theanine. The least expensive, Approved product cost 22 cents to obtain 200 mg of L-theanine while the cost was often 60 cents for other products (See What CL Found).
Save to favorites
This feature is restricted to active members.
Join now to save favorites and get all member benefits, including over 1,300 reviews.
Join NowAlready a member? Sign in here.
L-Theanine Supplements Review
Find the Best L-Theanine Supplement. Find Out If L-Theanine Helps for Stress and Which Products Are Best
Reviewed and edited by Tod Cooperman, M.D.
Alphabetical list of L-theanine supplement brands compared in this review
Bluebonnet L-Theanine
Country Life L-Theanine
GNC L-Theanine
Jarrow Formulas L-Theanine 200
Life Extension L-Theanine
NOW L-Theanine Double Strength
Puritan's Pride L-Theanine
Solgar L-Theanine
Source Naturals L-Theanine
Swanson Ultra Suntheanine
Thorne Research Theanine
TwinLab L-Theanine Dots
Vitamin World L-Theanine
Make sure the L-theanine supplement you take passed our test and is right for you!
Isn't your health worth it?
See the Review Now
Already a member? Sign in here.
Join now at www.consumerlab.com/join/
Summary
You must join to see the full review and test results for L-theanine supplements along with ConsumerLab.com recommendations and quality ratings. You'll get test results and quality ratings for 8 supplements selected for review by ConsumerLab.com, plus 4 others which passed the same tests through ConsumerLab.com's voluntary, Quality Certification Program. Plus, you'll learn:
- Which L-theanine supplements failed testing and which passed
- Differences in the marketed forms of L-theanine
- The best L-theanine supplements at the lowest cost
- The dosage of L-theanine taken for different applications and the related clinical evidence
- Potential side effects and drug interactions of L-theanine supplements
- Tips for buying and using L-theanine, and more!
Join to unlock the full report and get full access to over 1,300 reviews
See the Review NowAlready a member? Sign in here.
Join now at www.consumerlab.com/join/
Related CL Answers (6)
As a ConsumerLab.com member, you may print a copy of this report for your personal use.
You can access a special print version by clicking the "Print" icon in the upper right corner of this report. You can then use your web browser's print functions to print the whole report or just selected pages.
You may also email or post a link to this report using the web address above. Non-members using the link will see a free summary and can join to view the full report. Other means of copying or distributing this report, in part or full, are not permitted.
If you are sight-impaired and your computer is having trouble converting the text in this report to speech, contact us for assistance at Membership@ConsumerLab.com or by phone at 914-722-9149.
