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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 6 studies · 4 RCTs · 333 total participants
Confidence
ModerateBy outcome
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.
See full supplement plans that include Magnesium L-Threonate.
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Last reviewed June 2026 · evidence from 6 studies · how we score
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.
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.
Crosses into the CNS to elevate cerebrospinal magnesium more than other magnesium forms.
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.
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~1.5-2g magnesium-L-threonate daily (≈144mg elemental magnesium), often split into two doses
Take with food
| Form | Type |
|---|---|
| 💊Magnesium L-threonate (Magtein) | Recommended |
| 💊Capsule | Alternative |
| 🧪Powder | Alternative |
For general magnesium needs, cheaper forms suffice; this form is for brain-magnesium goals.
Minimum: 4 weeks
Optimal: 6 weeks
Cycling: Not required
Note: Often split into two doses, one in the evening.
Dose-response data unavailable. The current published research for Magnesium L-Threonate does not provide sufficient dose-specific outcome data to generate reliable dose-response curves.
Refer to the Dosage & Timing section above for recommended dose ranges based on available evidence.
Modest gains in memory and cognitive composite scores in early trials.
Faster reaction time reported in an RCT.
Some self-reported sleep improvement; objective sleep measures often unchanged.
Use caution — impaired magnesium excretion.
Standard magnesium needs apply; this specific form is not well studied in pregnancy.
Magnesium can reduce absorption — separate dosing by 2+ hours.
Magnesium can reduce absorption — separate dosing.
Tip: Lower dose; avoid stacking evening dose late
Tip: Take with food; reduce dose
Both supply magnesium; threonate targets the brain while standard magnesium covers general repletion.
Brain-targeted plus general magnesium status.
Magnesium is a cofactor in vitamin D metabolism.
Supports vitamin D activation alongside magnesium status.
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. The most commonly reported side effects are headache/drowsiness, GI upset. Use caution if any of these apply to you: Severe kidney impairment (magnesium accumulation risk).
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