Magnesium L-Threonate (Magtein)
Research Reliability -
The only magnesium form shown to meaningfully cross the blood-brain barrier, studied specifically for memory and synaptic density.
Appetite
Mood
Sleep
Magnesium L-Threonate (Magtein)
Description
While most magnesium forms support systemic relaxation and muscle function, magnesium L-threonate was specifically engineered (and patented as Magtein) to cross the blood-brain barrier far more effectively than other chelates, based on research showing it raises brain magnesium levels and increases synaptic density in animal models. Human trials in older adults with memory complaints showed improvements in working memory and executive function over several weeks. This makes it a distinct addition alongside, not a replacement for, magnesium bisglycinate or citrate in a stack — those forms are dosed for sleep and muscle relaxation, this one specifically for cognitive support.
Effects
First 2 weeks
subtle
Weeks 4–6
Ongoing
How It Feels
Gentle and cognitive rather than sedating; over four to six weeks some notice sharper recall and clearer thinking. Unlike bisglycinate, this form is dosed for the brain, not for sleep or muscle. Effects are subtle and build with consistency.
Evidence
Evidence Strength
Moderate (some human RCTs)
Caveats
Trials are relatively small and some are industry-funded on the specific branded Magtein ingredient; the underlying brain-magnesium mechanism is substantially derived from animal research.
Usage
Commonly Referenced Starting Amount
1,000 mg compound/day (about 72 mg elemental magnesium)
Commonly Referenced Amount
About 1,500–2,000 mg compound/day (roughly 144 mg elemental magnesium) is the dose used in the cognition research this ingredient is known for
Referenced Upper Limit
The same 350 mg/day supplemental elemental-magnesium upper limit applies here. The brain-specific cognitive claim rests mainly on one small human trial plus supporting animal work — promising, but a thinner evidence base than the mineral's overall safety profile
Onset
4–6 weeks
Biomarkers to Track
Subjective
(Daily)
Memory and word recall
Sleep quality
Mental clarity (1–10)
Objective
(Quarterly)
Cognitive testing battery (working memory, executive function)
RBC magnesium (intracellular status, more accurate than serum)
Very safe. This form is dosed for the brain rather than for sleep or muscle.
People with kidney disease should moderate total magnesium.
Expecting the sedation of bisglycinate, and taking it instead of, rather than alongside, other magnesium.
Disclaimer
This information is for educational purposes only and is not medical advice. It is not intended to diagnose, treat, cure, or prevent any disease. Consult a qualified healthcare provider before starting any new supplement, especially if you are pregnant, nursing, taking medication, or managing a health condition.
Liu G et al. (2016). Journal of Alzheimer's Disease, 49(4), 971-990. RCT (MMFS-01/branded magnesium L-threonate and cognition in older adults). PMID: 26519439. DOI: 10.3233/JAD-150538.
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