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Magnesium L-Threonate (Magtein)
A magnesium form designed to raise brain magnesium, with early human RCTs showing modest cognitive (memory/reaction-time) benefit — but small, partly industry-funded trials and mixed, mostly self-reported sleep results keep the evidence emerging.
What the evidence says
Most Magnesium L-Threonate studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from medium-quality randomised trials published 2010–2025 with a typical study size of 100 participants.
Based on 7 studies · 4 RCTs · 333 total participants
Confidence
Moderate confidenceBy outcome
Sits at Emerging 4.8 because a few small human RCTs show modest cognitive gains and the mechanism is appealing, but trials are small, partly industry-funded, lack meta-analyses, and sleep benefits are largely self-reported.
4 trials ongoing or recruiting · 8 completed on ClinicalTrials.gov
4 of the completed trials have posted results
Registered trials show research momentum for Magnesium L-Threonate, not proof of effect — a registration is a plan, and posted results are sponsor-reported, not peer-reviewed. They are never counted toward the evidence rating above.
Browse these trials on ClinicalTrials.govClinicalTrials.gov · as of Sep 2026
Magnesium L-threonate (branded Magtein) is a magnesium form developed specifically to cross into the brain and raise cerebrospinal magnesium, based on rodent work showing enhanced learning, memory, and synapse density.
Early human RCTs are promising but modest: a 6-week trial improved cognitive composite scores and reaction time (though not every test), and a trial in older adults with cognitive impairment showed a meaningful cognition benefit.
The sleep evidence is weaker and largely self-reported, with objective wearable measures unchanged in at least one trial. Several trials are small and/or industry-funded, so it sits at the emerging end despite the appealing mechanism.
It is a premium-priced form; standard magnesium glycinate/citrate is far cheaper for general magnesium repletion.
Designed to cross into the CNS and elevate brain magnesium more than other magnesium forms — but the superior brain-uptake evidence is largely preclinical (rodent); human trials measured cognition, not brain magnesium levels.
In animal models, increases synapse density and NMDA-receptor signaling tied to learning and memory.
Also corrects general magnesium status like any magnesium salt.
How Magnesium L-Threonate works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.
Use caution — impaired magnesium excretion.
Standard magnesium needs apply; this specific form is not well studied in pregnancy.
Magnesium chelates these antibiotics and reduces their absorption — separate dosing by several hours.
Magnesium reduces bisphosphonate absorption — separate dosing per bisphosphonate instructions.
Magnesium can reduce levothyroxine absorption — separate dosing by 4+ hours.
Tip: Lower dose; avoid stacking evening dose late
Tip: Take with food; reduce dose
Magnesium L-Threonate has an evidence score of 4.8/10 — emerging evidence based on 6 indexed studies. A magnesium form designed to raise brain magnesium, with early human RCTs showing modest cognitive (memory/reaction-time) benefit — but small, partly industry-funded trials and mixed, mostly self-reported sleep results keep the evidence emerging. Representative study: PMID 41601871.
The commonly studied dose of Magnesium L-Threonate is ~1.5-2g magnesium-L-threonate daily (≈144mg elemental magnesium), often split into two doses. Individual needs vary — start at the lower end of the range and adjust based on how you respond.
The best time to take Magnesium L-Threonate is in split doses through the day. Taking it with food is preferred. Trials commonly split the dose, with one portion in the evening.
Magnesium L-Threonate is generally well-tolerated and considered safe for most healthy adults at recommended doses. Reported side effects are uncommon and include headache/drowsiness, GI upset. Use caution if any of these apply to you: Severe kidney impairment (magnesium accumulation risk).
Magnesium
Probably helpsSupports 300+ enzymatic reactions — critical for sleep, stress response, muscle function, and cognitive health.
Creatine
Likely helpsIncreases phosphocreatine stores for faster ATP regeneration, boosting strength, power output, and cognitive function under stress.
Omega-3
Probably helpsEssential fatty acids critical for brain health, mood regulation, and reducing inflammation throughout the body.
Acetyl-L-Carnitine
Likely helpsAcetylated carnitine that crosses the blood-brain barrier to fuel mitochondrial energy and donate acetyl groups for acetylcholine synthesis.
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Reviewed by Dr. Baher Al Hakim · Last reviewed June 2026 · evidence from 7 studies · how we score · editorial policy
This information is for educational purposes only. It is not a substitute for professional medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement or medication.
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