Magnesium L-Threonate Dosage Chart
Magnesium L-threonate (Magtein) is a patented form developed by MIT researchers. It is the only magnesium compound shown in animal and preliminary human studies to significantly raise brain magnesium levels. Used primarily for cognitive function, memory, and neuroprotection.
Magnesium L-Threonate Dosage by Age Group
| Age Group | Age Range | Dose Range | Notes |
|---|---|---|---|
| Adults — cognitive support | 18–64 years | 1500–2000 mg | As magnesium L-threonate (not elemental) |
| Adults — elemental Mg equivalent | 18–64 years | 144–200 mg | ~8–10% elemental Mg from L-threonate salt |
| Seniors (65+) | 65+ years | 1500–2000 mg | Same dose; shown in older adult studies |
Weight-Based Dosage Calculator
Enter your weight to calculate a personalized Magnesium L-Threonate dose based on body weight. Some protocols use 25 mg/kg body weight (as L-threonate compound, not elemental Mg). A 70 kg adult = ~1,750 mg/day.
When and how to take Magnesium L-Threonate
The standard Magtein protocol is 3 capsules at night (2 g total). Alternatively, take 2 capsules before sleep and 1 in the morning. Take with or without food.
Available Forms
Patented form, most studied. Typically 667 mg per capsule.
Standard dose: 3 capsules/day = ~2 g L-threonate
Less common. Ensure it is true L-threonate salt, not threonate-adjacent compounds.
Verify supplier purity for non-branded powder
Safety Cautions
- Doses above 2,000 mg/day as L-threonate have not been well studied.
- Still counts toward the 350 mg/day UL for supplemental elemental magnesium.
- Some users report vivid dreams, headache, or mild grogginess — usually resolves after 1–2 weeks.
- Kidney disease patients should avoid without physician approval.
- Research is promising but limited — most studies are in animals or small human trials.
Frequently Asked Questions
What is the standard magnesium L-threonate dosage?
Clinical studies and the Magtein manufacturer recommend 2,000 mg/day of magnesium L-threonate (not elemental magnesium). This is typically split as 3 × 667 mg capsules, with 2 taken at night and 1 in the morning.
How is magnesium L-threonate different from other magnesium forms?
Magnesium L-threonate is the only form with strong evidence for crossing the blood-brain barrier and raising cerebrospinal fluid magnesium levels. Other forms (citrate, glycinate) are effective for systemic magnesium status but have limited brain penetration.
How long does it take to feel effects from magnesium L-threonate?
Most users notice improved sleep quality within 1–2 weeks. Cognitive effects (memory, focus) typically take 4–8 weeks to become apparent, consistent with neuroplasticity timelines.
Can I take magnesium L-threonate with other magnesium forms?
Yes, but be mindful of total elemental magnesium intake from all sources, which should stay below 350 mg/day from supplements. Magnesium L-threonate at 2,000 mg provides only ~160–200 mg elemental magnesium, leaving room to combine with small amounts of glycinate or citrate.
Sources & References
- Liu G et al., Neuropharmacology 2016 — Alzheimer's prevention with Mg-threonate
- MIT press release — Magtein development
- Slutsky I et al., Neuron 2010 — Enhancement of learning and memory by Mg