---
product_id: 7194707
title: "Source Naturals Magtein Magnesium L-Threonate, 667mg, Supports Focus, Mood, Healthy Memory, Cognitive Function - 180 Capsules"
brand: "source naturals"
price: "R$1002"
currency: BRL
in_stock: true
reviews_count: 8
url: https://www.desertcart.com.br/products/7194707-source-naturals-magtein-magnesium-l-threonate-667mg-supports-focus-mood
store_origin: BR
region: Brazil
---

# Sleep Quality Stress Resilience Cognitive Boost Source Naturals Magtein Magnesium L-Threonate, 667mg, Supports Focus, Mood, Healthy Memory, Cognitive Function - 180 Capsules

**Brand:** source naturals
**Price:** R$1002
**Availability:** ✅ In Stock

## Summary

> 🧠 Elevate Your Mind, Elevate Your Life!

## Quick Answers

- **What is this?** Source Naturals Magtein Magnesium L-Threonate, 667mg, Supports Focus, Mood, Healthy Memory, Cognitive Function - 180 Capsules by source naturals
- **How much does it cost?** R$1002 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.com.br](https://www.desertcart.com.br/products/7194707-source-naturals-magtein-magnesium-l-threonate-667mg-supports-focus-mood)

## Best For

- source naturals enthusiasts

## Why This Product

- Trusted source naturals brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Mood Uplift:** Experience a natural lift in mood and energy levels.
- • **Memory Mastery:** Support your episodic and working memory for peak performance.
- • **Made in the USA:** Crafted under strict cGMP standards for your peace of mind.
- • **Trust in Quality:** Join the Source Naturals family with over 40 years of excellence.
- • **Elevate Your Mind:** Unlock enhanced focus and cognitive function with every capsule.

## Overview

Source Naturals Magtein Magnesium L-Threonate offers 667mg of a unique magnesium compound designed to enhance cognitive function, mood, and memory. With 180 capsules per bottle, this product is manufactured in the USA under stringent quality standards, ensuring you receive a trusted supplement for optimal health.

## Description

Full description not available

## Features

- MAGTEIN BENEFITS. Known to increase resilience to stress, lift mood, raise your energy levels, improve concentration and focus and reformation of sleep quality.
- BENEFITS COGNITIVE ABILITY. There are 4 aspects of cognitive ability that they were positively effected by taking Magtein, episodic memory, working memory, executive function, and attention.
- EXCELLENT SOURCE OF MAGNESIUM L THREONATE. There are countless ways to get other forms of magnesium naturally in your diet, but food sources of magnesium L threonate do not exist because it’s a synthesized form.
- OVER 40 YEARS OF TRUST. Source Naturals was created in 1982 by CEO Ira Goldberg to support each individual's potential to enjoy optimal health.
- MANUFACTURED IN THE USA. Manufactured in Scotts Valley, CA, under the Good Manufacturing Practices (cGMPs) established by the US Food and Drug Administration. (FDA)

## Product Details

- **Brand:** Source Naturals
- **Item Form:** Capsules
- **Primary Supplement Type:** Magnesium
- **Unit Count:** 180.0 Count
- **Flavor:** Unflavored

## Images

![Source Naturals Magtein Magnesium L-Threonate, 667mg, Supports Focus, Mood, Healthy Memory, Cognitive Function - 180 Capsules - Image 1](https://m.media-amazon.com/images/I/61K88UFg5JL.jpg)

## Available Options

This product comes in different **Flavor Name, Size** options.

## Questions & Answers

**Q: 3 capsules contain 2 gm magnesium l-threonate and 144 mg of magnesium.  How much L-threonate is this?   Product label says nothing.**
A: Hi...  The l-threonate is just a metabolite (salt) of vitamin C that is bound to the magnesium as a chelation agent to supposedly make the magnesium more bioavailable, particularly in the brain.  It's not a substance that acts independently, or is counted independently, of the magnesium.  It takes 2 gm of magnesium l-threonate to get 144 mg of actual elemental magnesium, such as you might find in more commonplace magnesium supplements... it's just that binding the magnesium with a chelation agent (in this case l-threonate) may make each mg of magnesium more bioavailable (esp in the brain), than larger amounts of regular magnesium.  Wonder if you're thinking of, and maybe looking for, l-theanine?  That's a totally different substance (supposed to provide a relaxed alertness) from green tea.  If that's what you want, it is available as its own thing.

**Q: why does my bottle show Maltodextrin in the "other ingredients" but on the website label it does not show it?  I bought this based on the ingredients.**
A: This problem needs to be addressed and not pawned off. The June/July2016 reviews have a higher level of complaints. Update the photos if the manufacturer has changed ingredients!

**Q: why 2000 mg in some and 645 mg in others**
A: 2000 mg of magnesium threonate will yield 144 mg of elemental magnesium.  This seems to be the recommended daily dosage.  Three capsules, each containing 645 mg of magnesium threonate will be needed to give a daily dosage of 1935 mg (which is the same as 2000 mg within rounding error).  But some brands use two larger capsules to provide the recommended daily dosage and these may be harder to swallow for some people.

**Q: Is it best to take with food or on empty stomach?**
A: Best on an empty stomach.  I take 2 am and 1 pm.  Directions are 3 per day with 1 taken a few hours before bedtime and 2 taken during the day.  I read that magnesium absorbs best on an empty stomach and some supplement instructions recommend taking that way also.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Passes the blood/brain barrier
*by J***G on August 11, 2025*

This is an excellent product. It passes the blood/brain barrier. Helps generally and in preventing headaches.

### ⭐⭐⭐⭐⭐ I began to feel this comforting sense of peace and joy. Since I have some genetic issues with absorbing ...
*by T***N on October 13, 2015*

I have been taking Magtein for several months. After just a few days, I began to feel this comforting sense of peace and joy. Since I have some genetic issues with absorbing folate, I have been taking numerous supplements for years to treat a number of conditions. Hence, I am already on some of the vitamins and minerals that should be taken with Magnesium. Especially, B6 and D3. Off and on over the years I would take Magnesium to treat restless legs, but it was only sporadic and not l-threonate. Knowing there is a strong family history of dementia, I decided to switch to Magtein in the hopes that it might delay the onset of Alzheimer's. Not for one minute do I believe this will be a miracle cure, but it might be part of a larger arsenal of preventative measures. Regardless, this is now one of the top 5 things I have discovered to improve my daily life with lessened anxiety and heightened clarity of thought and deeper sleep.I recommended this to my adult son and he promptly hijacked my bottle for himself! I am making him pay me back. He has suffered from anxiety for over a decade and cannot tolerate the side effects of numerous anti-anxiety prescriptions. After taking this, he reports his anxiety has lessened a great deal and that his wife is grateful. He also reports that he had been experiencing brain fog and had begun slurring some of his words. Those two things are now better. This is the first medication/supplement he has tried that he has wanted to keep taking other than a multivitamin.We are waiting to see how this affects my mother who is in the middle stages of Alzheimer's. I am hopeful that it will also ease her anxiety and I don't have any unrealistic expectations that it will treat her dementia. But, if it does . . . wouldn't that be great! Alas, anything that will help keep her calm is a good thing. She has had very bad reactions to prescriptions in the past and refuses anything "for her brain." We can open the capsule and mix the powder into her food if she refuses it in pill form. We have only been using this for a week and just one a day, so too early to report.

### ⭐⭐⭐⭐⭐ Magtein, reg trademarked Magnesium Threonate, works for relaxation, sleep
*by S***0 on July 7, 2025*

Amazing product, leagues above the rest

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*Product available on Desertcart Brazil*
*Store origin: BR*
*Last updated: 2026-01-23*