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

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In Stock
  • Expiration Date: Jun 2018
  • Shipping Weight: 0.17 lbs (0.08 kg)
  • 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

No noticeable effect for me.

Posted by 5308342432213357870 on Oct 22, 2016

Wish I could feel the difference, but unfortunately both my boyfriend and I don't feel any different / more relaxed after eating this.

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Too many side effects

Posted by 5225468070068524397 on Sep 27, 2016

This product had a sedative effect on me as a sleep aid, but it caused headaches, lethargy, depression, palpitations and general feeling of being unsettled. I stuck it out for a few days, hoping I'd get used to it, but will not continue with it any longer.

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six stars! 六顆星!!!!!

Posted by cattylee on Aug 21, 2016


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Drs Best Suntheannine

Posted by 5500624427986695631 on Aug 20, 2016

I have been using this for some time now as a chill poll, taking regularly to help me stay calm and chilled out throughout the day and have found it works effectively to calm me down.

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Posted by Reviewer1377782 on Jun 30, 2016

I have been suffering the sudden loss of my brother at the age of 69 years old - 2 years older than me, and my nerves have been shattered. I have been unable to cope with anything. Following the shock, my rheumatoid arthritis flared miserably and I was in severe pain for a few weeks. I would wake in the morning and find my heart beating faster than normal. I was not able to breath properly and my anxiety and fear levels were very high. I immediately started taking extra magnesium and G.R.Lanes 'Quiet life ' tablets - 2 in the morning before I got up. Also, before I got up I would take about 150 mg. GABA which slowed my heart rate to normal and I would take a capsule of Tulsi tea powder which gave me a feeling of centred calm. However, while this all brought me down to a near normal state, I still could not bring myself to go to the doctor let alone my usual yearly visit to the Rheumatology department at the hospital. I read about this product as I searched frenetically online for help or for someone else who has suffered in the same way and went to iherb to see if they stocked it and so I bought it. I found my hospital appointment was three days away instead of my usual June date, forgetting that they had changed it. I had a panic attack and planned to make an excuse not to go as my nerves were still extremely bad and I panicked at every opportunity that they chose. On the day of my hospital appointment, my order for suntheanine arrived EARLY - it wasn't due for another three days, so, I took 1 capsule about an hour before I my appointment. As we left home I started to panic but controlled it with breathing and thinking of my brother in Heaven enjoying himself and talking to our parents who have also gone to Heaven, then about half an hour later, as we got nearer the hospital, I realised that I was calm, with a non drowsy calm that I hadn't felt for many months. I felt so normal that I told the doctor about how I felt and what I took to get in this normal state. I got through this traumatic time easily and the feeling of non drugged calm released so much tension that I cried like it was in fashion. I have this each morning now and I am noticing I am able to cope 100% better without taking all those other natural calmers. AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ several million times.

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