---
product_id: 792408716
title: "Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count"
brand: "doctor's best"
price: "€ 48.11"
currency: EUR
in_stock: true
reviews_count: 7
category: "Doctor's Best"
url: https://www.desertcart.hr/products/792408716-doctors-best-l-theanine-contains-suntheanine-helps-reduce-stress-sleep
store_origin: HR
region: Croatia
---

# 100% patented pure L-Theanine from green tea 150 mg Suntheanine per capsule Crosses blood-brain barrier in 30 minutes Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count

**Brand:** doctor's best
**Price:** € 48.11
**Availability:** ✅ In Stock

## Summary

> 🧘‍♂️ Unlock calm focus—because your brain deserves the best.

## Quick Answers

- **What is this?** Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count by doctor's best
- **How much does it cost?** € 48.11 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.hr](https://www.desertcart.hr/products/792408716-doctors-best-l-theanine-contains-suntheanine-helps-reduce-stress-sleep)

## Best For

- doctor's best enthusiasts

## Why This Product

- Trusted doctor's best brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Clean & Conscious:** Gluten-free, vegan capsules crafted without additives for mindful wellness.
- • **Pure Green Tea Power:** Sourced from premium Japanese green tea leaves, ensuring natural, non-GMO, vegan-friendly quality.
- • **Trusted & Top-Ranked:** Join thousands of professionals who rate it 4.6 stars and trust Doctor’s Best for daily balance.
- • **Clinically Proven Calm:** Experience focused relaxation with 150 mg of Suntheanine, the purest form of L-Theanine.
- • **Fast-Acting Brain Boost:** Crosses the blood-brain barrier within 30 minutes to deliver quick mental clarity and stress relief.

## Overview

Doctor's Best L-Theanine delivers 150 mg of Suntheanine, a patented pure amino acid from Japanese green tea, clinically shown to promote relaxation and mental clarity by crossing the blood-brain barrier within 30 minutes. This vegan, gluten-free supplement supports stress reduction and restful sleep, trusted by thousands with a 4.6-star rating.

## Description

Suntheanine l-theanine contains 100% suntheanine, a patented pure form of the amino acid l-theanine produced in japan from green tea leaves. this award-winning brand of theanine has been the subject of numerous safety studies and human clinical trials. one of green tea's natural health-promoting compounds, l-theanine (y-glutamylethylamide) is synthesized in the roots of tea plants and transported to the leaves, comprising about 2% of the total dry weight of green tea leaves. it is the ingredient that is responsible for both the taste and the relaxing effects of green tea. research shows that supplemental l-theanine crosses the blood-brain barrier within 30 minutes of intake and thus is able to exert its effects directly on the brain.

Review: It not bad - Not bad overall but I didn't get the full effect from it
Review: Not effective - Not effective and cannot return the product either

## Features

- Form: Capsules
- Count: 90
- Serving Size: 1 Capsule
- This is a vegetarian product
- Dietary Supplement

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B001OXTGVG |
| ASIN  | B001OXTGVG |
| Additives | Amino Acid |
| Age Range Description | Adult |
| Allergen Information | Gluten Free |
| Best Sellers Rank | #6,700 in Health ( See Top 100 in Health ) #22 in Weight Loss Supplements |
| Brand | Doctor's Best |
| Customer Reviews | 4.6 4.6 out of 5 stars (2,362) |
| Customer reviews | 4.6 4.6 out of 5 stars (2,362) |
| Date First Available | 3 August 2012 |
| Department  | Health and Beauty>Health and Wellness |
| Format | Capsule |
| Is Discontinued By Manufacturer  | No |
| Item model number  | DRB-00197 |
| Manufacturer  | Doctor's Best |
| Product Dimensions  | 5.41 x 5.41 x 9.37 cm; 60 g |
| Product Name | L-Theanine |
| Serving Recommendation | One Capsule |
| Units | 90 Count |
| Weight | 0.15 Kilograms |

## Product Details

- **Brand:** Doctor's Best
- **Diet type:** Gluten Free
- **Flavour:** Unflavored
- **Item dimensions L x W x H:** 5.4 x 5.4 x 9.4 centimeters
- **Item form:** Capsule
- **Item weight:** 0.06 Kilograms
- **Primary supplement type:** multivitamin
- **Product benefits:** Stress Relief
- **Special ingredients:** Amino Acid
- **Unit count:** 90 Count

## Images

![Doctor's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count - Image 1](https://m.media-amazon.com/images/I/719zn9vom2L.jpg)

## Questions & Answers

**Q: How do you choose between their Suntheanine and their 5-HTP? Both seem to do the same thing.**
A: 5-HTP is the tryptophan-based intermediate to serotonin which most antidepressants work to increase or support.
It's more specifically targets serotonin, needed for a balanced mood.

Suntheanine, a patented and advanced form of L-Theanine, has a broader range of psychotherapeutic and neuro- cognitive benefits than does 5-HTP.

It works as an anti-anxiety from multiple paths. 1) It supports the levels of gaba to calm the brain 2)It blocks glutamate receptors in the brain from receiving an excitatory neurotrans-mitter 3) It induces Alpha Waves in the brain.

Additionally, as a small molecule powerful antioxidant, it crosses the blood brain barrier to reach neurons directly where it fight oxidation in them. 

This gives it the ability to fight or offer benefit against a wide range of age-related neuro-cognitive conditions such as memory loss, learning impairments, attention deficits, dementia, Alzheimer's etc.

**Q: Has anyone taken Suntheanine by opening the capsules and adding to liquid?  If so, how is the taste?**
A: My daughter, after first asking the doctor if it was safe, decided to try it with her Autistic child.  Since she can't swallow pills, my daughter opens the capsule and places it into applesauce or a similar food.   It still seems effective and my grandchild didn't seem to mind or notice any bad taste.  So, I assume if it can be placed in food, it should be fine to also place it in a liquid.  I hope this has helped you with your questions.

**Q: I see some theanine comes from China. I would prefer one produced in the USA. Does any ingrediant in this come from China?**
A: What is the country of origin for Doctor's Best products?Doctor's Best products are quality tested and manufactured in the United States using highly qualified cGMP manufacturers and raw material ingredients. Doctor's Best sources raw materials from around the world and ingredients are subject to the intense testing and verification regardless of geography of origin.- See more at: http://www.drbvitamins.com/products/suntheanine-l-theanine-150mg/drb-00197#sthash.wAlbJQD6.dpuf

**Q: Does this contain caffiene?**
A: It doesn't state anywhere on the bottle that it contains caffeine. I'm not sure, you will have to investigate further.

## Customer Reviews

### ⭐⭐⭐ It not bad
*by A***I on 7 May 2023*

Not bad overall but I didn't get the full effect from it

### ⭐ Not effective
*by A***S on 14 March 2022*

Not effective and cannot return the product either

### ⭐⭐⭐⭐⭐ Review
*by M***4 on 28 December 2025*

I find this particular formulation of L-Theanine to be a very good adjunct to help me fall asleep and stay asleep. This formula by the Doctor's Best brand has "Suntheanine," which is a patented form of the amino acid L-Theanine known to promote relaxation. I've taken this formula steadily for about a year at bedtime with only good results as part of an overall sleep hygiene routine that also includes listening to a Calm sleep story on the app in my phone, next to my bed. Also why I like this particular formulation is that it has just 150 mg of the Suntheanine/L-theanine in it, which is less than most other formulas on the market. IMO, less of something often translates to "more." I don't know how long it stays in the system, but probably not for very long, because I wake up normally, with no leftover drowsiness. Another reason why I like this supplement is because it's NON-hormonal. Some folks use melatonin to promote sleep, but I've always avoided that, since melatonin is a hormone, and from what I understand, it's not meant to be used long-term. For me, this has performed as a safe and effective over-the-counter sleep aid. As of December 2025, it was still reasonably priced.

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---

*Product available on Desertcart Croatia*
*Store origin: HR*
*Last updated: 2026-03-08*