---
product_id: 1864778
title: "Doctor's BEST L-Theanine Caps 150 mg, for Men & Women, 90 Veg Capsules"
brand: "doctor's best"
price: "¥7385"
currency: JPY
in_stock: true
reviews_count: 10
category: "Doctor's Best"
url: https://www.desertcart.jp/products/1864778-doctors-best-l-theanine-caps-150-mg-for-men-women
store_origin: JP
region: Japan
---

# Supports alertness without drowsiness Non-GMO, vegan & gluten-free veggie capsules 150 mg pure Suntheanine per capsule Doctor's BEST L-Theanine Caps 150 mg, for Men & Women, 90 Veg Capsules

**Brand:** doctor's best
**Price:** ¥7385
**Availability:** ✅ In Stock

## Summary

> 🧘‍♂️ Stay sharp, stay calm — the smart way to own your day!

## Quick Answers

- **What is this?** Doctor's BEST L-Theanine Caps 150 mg, for Men & Women, 90 Veg Capsules by doctor's best
- **How much does it cost?** ¥7385 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/1864778-doctors-best-l-theanine-caps-150-mg-for-men-women)

## 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

- • **Pure Focus Fuel:** 150 mg of clinically-backed Suntheanine to sharpen your mental edge.
- • **Clean & Conscious:** Vegan, gluten-free, soy-free capsules that fit your mindful lifestyle.
- • **Stress-Free Hustle:** Promotes calm and relaxation without compromising your productivity.
- • **Effortless Wellness:** Easy-to-swallow veggie capsules designed for daily convenience.
- • **Trusted Science, Proven Results:** Backed by 35+ years of rigorous research and quality assurance.

## Overview

Doctor's BEST L-Theanine Caps deliver 150 mg of pure Suntheanine per vegan capsule, promoting relaxation and mental clarity without drowsiness. Perfect for professionals seeking stress relief and enhanced focus, this non-GMO, gluten-free supplement is crafted with over 35 years of scientific expertise to support your balanced, high-performance lifestyle.

## Description

At Doctor’s Best, we understand that stress can be an unwelcome guest. That is why our specialized formula features a pure form of L-theanine that is renowned for promoting relaxation, managing stress, and sharpening focus for a more balanced state of mind.*

Review: Very good NON-hormonal OTC supplement that promotes relaxation at bedtime. - 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.
Review: Great price on L-Theanine! - L-Theanine was first recommended to us by a psychiatrist for our younger son when he was in 4th grade and developed a tic due to stress of a teacher in a new school. It didn't do anything for the tic, but our older son took some one day, and really felt great! He's in high school and had been feeling pretty stressed. He said it helped him feel calmer and less anxious while not losing any focus. The good thing is L-Theanine is an amino acid; it's found in green tea. It can cross the blood brain barrier and has a positive effect on alpha-brain waves; it has a relaxing effect, reducing physical and mental stress, boosts mood and cognition. It also acts in concert with caffeine to boost cognitive performance. L-Theanine has been tested on small groups of people with significant sleep disorders, and while it's not overly sedating, it does affect alpha waves and tends to be relaxing. It helps those people with sleep, as it does with anxiety. My husband and I recently added it to our desertcart subscription list of supplements when we read an article in Life Extention Foundation's December 2013 magazine about supplements one should consider adding when facing the flu. It was incredibly timely! No sooner did I get the magazine, read it, stock up and get enough for all the kids, than I got socked with a sinus infection/flu. I have never before gone without a course of antibiotics, but this time really wanted to make the effort. I hunkered down with my supplements - L-Theanine included, ate cooked mushrooms (natural anti-viral) several times, as well as maintaining good hydration, and stayed in bed. I finally made it through my very first painful sinus infection/flu w/o antibiotics! So, yes, I heartily recommend L-Theanine! I'll keep buying it for myself, my husband, and our kids!

## Features

- L-THEANINE SUPPLEMENT: Each capsule provides 150 mg of Suntheanine, a pure form of L-theanine (the amino acid found in green tea). It is known for its supportive role in relaxation & mental clarity
- TENSION & STRESS SUPPORT: L-theanine helps encourage a relaxed state without drowsiness, supporting a sense of calm during everyday stress while still allowing for alertness and focus
- PROMOTES FOCUS: This supplement supports cognitive performance by promoting attention and mental sharpness, beneficial for work, study, or other focus-driven activities
- 150 MG VEGGIE CAPS: Doctor's Best L-Theanine comes in convenient, easy-to-swallow veggie capsules. This formula is Non-GMO, gluten free, soy free, and vegan-friendly, fitting a variety of lifestyles
- DOCTOR'S BEST: Good nutrition starts with sound science. For over 35 years, we have been dedicated to providing only thoroughly researched, rigorously tested, and clinically-approved supplements

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B001OXTGVG |
| Age Range Description | Adult |
| Allergen Information | Gluten Free |
| Best Sellers Rank | #11,790 in Health & Household ( See Top 100 in Health & Household ) #6 in 5-HTP Nutritional Supplements #1,146 in Sales & Deals |
| Brand | Doctor's BEST |
| Brand Name | Doctor's BEST |
| Color | No Color |
| Container Type | Bottle |
| Customer Reviews | 4.6 out of 5 stars 2,505 Reviews |
| Diet Type | Gluten Free |
| Dosage Form | 150 |
| Flavor | Unflavored |
| Item Dimensions | 2.13 x 2.13 x 3.69 inches |
| Item Form | Capsule |
| Item Nype Name | L-Theanine |
| Item Weight | 0.06 kg |
| Manufacturer | Doctor's Best |
| Manufacturer Part Number | DRB-00197 |
| Material Features | Vegetarian |
| Model Name | r's Best L-Theanine Contains Suntheanine, Helps Reduce Stress & Sleep, Non-GMO, Gluten Free, Vegan, 150 mg (DRB-00197), 90 Count |
| Model Number | DRB-00197 |
| Number of Items | 1 |
| Primary Supplement Type | multivitamin |
| Product Benefits | Relaxation |
| Specific Uses For Product | L-Theanine (Suntheanine®) 150 mg |
| Total Servings Per Container | 90 |
| UPC | 753950001978 |
| Unit Count | 90 Count |

## Product Details

- **Age Range (Description):** Adult
- **Brand:** Doctor's BEST
- **Diet Type:** Gluten Free
- **Flavor:** Unflavored
- **Item Form:** Capsule
- **Item Weight:** 0.06 kg
- **Item dimensions L x W x H:** 2.13 x 2.13 x 3.69 inches
- **Primary Supplement Type:** multivitamin
- **Product Benefits:** Relaxation
- **Unit Count:** 90 Count

## Images

![Doctor's BEST L-Theanine Caps 150 mg, for Men & Women, 90 Veg Capsules - Image 1](https://m.media-amazon.com/images/I/719zn9vom2L.jpg)

## Questions & Answers

**Q: What is curcumin?**
A: Curcumin is a natural compound found in turmeric root known for its antioxidant properties and nutritional support for joint and overall wellness.*

**Q: What are the benefits of curcumin?**
A: Curcumin supports joint comfort, mobility, and antioxidant activity that helps protect cells from oxidative stress.*

**Q: Why better absorption?**
A: This formula includes BioPerine black pepper extract standardized to 95% piperine, which helps enhance curcumin absorption and bioavailability.*

**Q: Is this derived from turmeric root?**
A: Yes. The curcumin in this formula is derived from turmeric root and standardized as Curcumin C3 Complex.*

**Q: What's the daily dosage?**
A: Adults typically take 2 capsules daily with food, or as recommended by a nutritionally informed physician.*

## Customer Reviews

### ⭐⭐⭐⭐⭐ Very good NON-hormonal OTC supplement that promotes relaxation at bedtime.
*by M***4 on December 28, 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.

### ⭐⭐⭐⭐⭐ Great price on L-Theanine!
*by J***S on January 20, 2014*

L-Theanine was first recommended to us by a psychiatrist for our younger son when he was in 4th grade and developed a tic due to stress of a teacher in a new school. It didn't do anything for the tic, but our older son took some one day, and really felt great! He's in high school and had been feeling pretty stressed. He said it helped him feel calmer and less anxious while not losing any focus. The good thing is L-Theanine is an amino acid; it's found in green tea. It can cross the blood brain barrier and has a positive effect on alpha-brain waves; it has a relaxing effect, reducing physical and mental stress, boosts mood and cognition. It also acts in concert with caffeine to boost cognitive performance. L-Theanine has been tested on small groups of people with significant sleep disorders, and while it's not overly sedating, it does affect alpha waves and tends to be relaxing. It helps those people with sleep, as it does with anxiety. My husband and I recently added it to our Amazon subscription list of supplements when we read an article in Life Extention Foundation's December 2013 magazine about supplements one should consider adding when facing the flu. It was incredibly timely! No sooner did I get the magazine, read it, stock up and get enough for all the kids, than I got socked with a sinus infection/flu. I have never before gone without a course of antibiotics, but this time really wanted to make the effort. I hunkered down with my supplements - L-Theanine included, ate cooked mushrooms (natural anti-viral) several times, as well as maintaining good hydration, and stayed in bed. I finally made it through my very first painful sinus infection/flu w/o antibiotics! So, yes, I heartily recommend L-Theanine! I'll keep buying it for myself, my husband, and our kids!

### ⭐⭐⭐⭐⭐ Great natural sub for Zanax/Sleep
*by A***R on September 17, 2026*

This and/or Ashwaghanda works well for calm and sleep. Amazing.

## Frequently Bought Together

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-09-29*