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Doctor's Best, Suntheanine L-Theanine, 150 mg, 90 Veggie Caps

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  • Product Code: DRB-00197
  • UPC Code: 753950001978
  • Package Quantity: 90 Veggie Caps
  • Dimensions: 4 x 2.1 x 2.1 in, 0.1 lbs (0.05 kg)
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Product Overview


  • Science-Based Nutrition
  • Dietary Supplement
  • Helps Promote Relaxation without Drowsiness
  • Helps Reduce Stress and Tension
  • Vegan

Suntheanine is the premier, patented form of the amino acid L-theanine. Suntheanine is the purest form of L-theanine on the market today. L-theanine is an amino acid derived from green tea that is responsible for the relaxation-inducing effect of tea consumption.

  • Helps promote a relaxed state without drowsiness.
  • Helps ease stress and everyday nervous tension.
  • Helps promotes a healthy mood and alertness.

Suggested Use

Suggested Adult Use: Take 1 capsule daily away from food, or as recommended by a nutritionally-informed physician.

Other Ingredients

Microcrystalline cellulose, modified cellulose (vegetarian capsule)

Non-GMO, gluten-free, vegan


Store in a cool dry place.

Supplement Facts
Serving Size: 1 capsule
Serving Per Container: 90 servings
  Amount Per Serving %Daily Value
Suntheanine L-theanine 150 mg
†Daily Value not established.
iHerb Customer Reviews
5 Stars
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1 Stars

A great product for stress

Posted by Reviewer2585485 on Jun 24, 2016

I take this product for stress and it is very good. Highly recommended!

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Seems to lower appetite

Posted by 5539113384560379125 on Jun 09, 2016

I've used it for a while, and there were some interesting effects, but they were one-off. One thing that seems to persist is that I'm less hungry, when I take it.

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Pleasantly Surprised!

Posted by Sickness-ELIMINATOR on Jun 03, 2016

I started with 150mg at bedtime, and found it lowers my morning fasting blood sugar! I did not expect this, but discovered it while I was testing frequently. This may be due to the comments I see on the net that theanine can lower cortisol...which is considered a factor in some "dawn phenomenon" patients with insulin resistance/type II diabetes. I don't know if this is really the explanation, but it certainly lowered my morning fasting glucose readings by 30pts or more! During the course of this bottle which is a 90 ct size, our home has had a major stressor, and grief generator, and I have been very upset during this time. So last night I took 300mg instead of the usual 150mg. I slept more soundly, and awakened with a less "heavy heart"...which is what I call my anxiety grief reaction to the acute/temporary stress here. If I feel the return of this anxiety today, I'll take 150mg in the daytime, and another 300mg at bedtime. I am very pleased with this product for myself. But I do think people may vary in their responses. And I think perhaps a higher dose may work for those that are not satisfied with 150mg a day. . . . You can find other products I use on my Page!

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Helps with sleep

Posted by 5206100159286206775 on May 25, 2016

Theanine with Tryptophan helps with sleep on the occasional nights when I'm awake in the middle of the night.

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effective stuff

Posted by 5355254441692460143 on May 19, 2016

I didn't expect this product to help me sleep-- more just for general relaxation-- but it really does. I have found it particularly useful for insomnia related to stress, anxiety, etc. A very handy product to have around for such times. Recommended.

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