Sports Research® Magnesium L-Threonate Capsules 2000mg - High-Absorption Magtein® for Enhanced Brain Health, Memory, Focus & Restful Sleep Support - Vegan · Non-GMO · Gluten Free - 180 Count
$0.33/serving
Price verified Apr 22, 2026
Not evaluated by the FDA · Individual results may vary · Consult a healthcare provider before use
Our verdict
2000mg Magnesium L-Threonate (144mg elemental Mg) per 4-capsule serving, 180 capsules of Magnesium L-Threonate (as Magtein, patented MIT ingredient) — 2000mg per 4-capsule serving (144mg elemental magnesium) per capsule from…
Why we recommend this
Magnesium L-Threonate with Magtein is categorically different from standard magnesium supplements — it is the only form with published evidence of crossing the blood-brain barrier and increasing synaptic magnesium density. For those prioritizing cognitive health, memory, and sleep quality, Sports Research's 2000mg Magtein formula — Non-GMO Verified, vegan, and third-party tested — is the premium choice. Backed by 2,173 reviews at 4.7 stars.
Check for interactions
Already taking other supplements or prescription medications? Add them below to check for documented interactions, severity, and clinical guidance.
Our database currently documents 137+ supplement and drug-category interaction pairs. Combinations not flagged here may still interact — always consult your healthcare provider before combining supplements, especially with prescription medications.
What to watch out for
Magnesium L-Threonate is optimized for brain delivery, not general magnesium repletion. Users with widespread magnesium deficiency should pair this with a higher-elemental-magnesium form like glycinate or malate to address systemic needs.
Dose & form
- Serving
- 2000mg Magnesium L-Threonate (144mg elemental Mg) per 4-capsule serving, 180 capsules
- Form
- Capsule
- Clinical range
- 200-400mg elemental magnesium daily
- Dose adequacy
- Full
- Supply
- 180 servings · $0.33/serving
- UPC
- 023249092087
Who it's best for
Adults seeking a brain-targeted magnesium form that crosses the blood-brain barrier to support memory, focus, and sleep quality
Who should skip it
Those needing general whole-body magnesium repletion (glycinate or malate are more elemental-efficient) or those on tight supplement budgets
Pros
- Magtein is the only magnesium form clinically shown to effectively cross the blood-brain barrier and raise brain magnesium levels
- 2000mg matches the top of the clinical dose range studied in published MIT and subsequent trials
- 180-capsule bottle provides a 45-day supply, reducing reorder frequency versus 90-count competitors
- 2,173 reviews at 4.7 stars confirms strong consumer satisfaction for this premium cognitive magnesium form
Cons
- Magtein provides only 144mg of elemental magnesium per serving — inefficient for correcting whole-body magnesium deficiency
- Requires 4 capsules per day, which is a higher pill burden than single-capsule alternatives
- Premium-priced at $58.95 compared to standard magnesium glycinate or citrate products
What customers say
4.7★ across 2,173 Amazon reviews. The most common questions from shoppers: re any potential interactions with medications, re any side effects from long-term use, and cause any digestive issues or side effects. Full answers in the FAQ below.
Frequently Asked Questions
What is the clinical dose for Magnesium L-Threonate (as Magtein, patented MIT ingredient) — 2000mg per 4-capsule serving (144mg elemental magnesium)?
What is the clinical dose for Magnesium L-Threonate (as Magtein, patented MIT ingredient) — 2000mg per 4-capsule serving (144mg elemental magnesium)?
Clinical trials typically use 200-400mg elemental magnesium daily. Sports Research Magnesium L-Threonate 2000mg with Magtein (180 Capsules) delivers 2000mg Magnesium L-Threonate (144mg elemental Mg) per 4-capsule serving, 180 capsules, which we classify as Full relative to that range.
How does Sports Research Magnesium L-Threonate 2000mg with Magtein (180 Capsules) compare to similar Capsule?
How does Sports Research Magnesium L-Threonate 2000mg with Magtein (180 Capsules) compare to similar Capsule?
See the "Also consider" section below for two alternatives. Choose based on form preference (Capsule vs alternatives), dose adequacy, and third-party testing.
Is Sports Research Magnesium L-Threonate 2000mg with Magtein (180 Capsules) third-party tested?
Is Sports Research Magnesium L-Threonate 2000mg with Magtein (180 Capsules) third-party tested?
Yes — Yes — Non-GMO Project Verified, cGMP-compliant, third-party tested. Third-party testing verifies ingredient identity and label accuracy.
Does this work with Amazon Subscribe & Save?
Does this work with Amazon Subscribe & Save?
Yes — Amazon Subscribe & Save is available for this product. Enrolling locks in a recurring delivery at a reduced per-unit price.
Are there any potential interactions with medications?
Are there any potential interactions with medications?
Magnesium supplementation can interact with antibiotics (tetracyclines, fluoroquinolones), bisphosphonates, and certain blood pressure medications. Separate magnesium supplements from these medications by at least 2 hours. Consult your physician if you take any chronic medications.
Are there any side effects from long-term use?
Are there any side effects from long-term use?
Magnesium L-Threonate is considered safe for long-term use. Some individuals experience mild drowsiness, making evening dosing popular for sleep support. GI effects are uncommon at recommended doses.
Does it cause any digestive issues or side effects?
Does it cause any digestive issues or side effects?
Magtein is generally better tolerated than magnesium oxide or citrate for GI side effects. Loose stools or nausea are uncommon but can occur at high doses — taking with food minimizes this risk.
Can it be taken with other supplements or vitamins?
Can it be taken with other supplements or vitamins?
Magnesium L-Threonate pairs well with vitamin D3 (which depends on magnesium for conversion), K2, omega-3s, and other sleep-supporting supplements like glycine or L-theanine.
Are there any specific instructions for taking it safely?
Are there any specific instructions for taking it safely?
Take four capsules daily, ideally split between a morning dose for focus and an evening dose for sleep support. Always take with food to minimize GI discomfort. Store in a cool, dry location.
How long until benefits are typically experienced?
How long until benefits are typically experienced?
Cognitive benefits such as improved focus and memory consolidation may be noticed within 4 to 8 weeks of consistent daily use. Sleep quality improvements are often reported sooner, within 1 to 2 weeks.
Also consider
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