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Magnesium L-Threonate

The only magnesium salt with credible evidence for raising brain (CSF) magnesium beyond what oral Mg from other forms achieves.

Aliases (6)
Mg L-threonate · Magtein · MgT · Magnesium threonate · L-Threonic acid magnesium salt · MAGNESIUM L-THREONATE
TYPICAL DOSE
2 g Magtein/day = ~144 mg elemental Mg/day, tak…
Pre-bed
ROUTE
CYCLE
STORAGE

Overview

What is Magnesium L-Threonate?

Magnesium L-threonate (Magtein) is a magnesium salt of L-threonic acid developed for enhanced central nervous system penetration. It is used as a cognitive and sleep-support supplement.

Key Benefits

Raises brain magnesium more effectively than other forms, supports memory and executive function, improves sleep quality, and may benefit anxiety, attention, and age-related cognitive decline.

Mechanism of Action

L-threonate facilitates magnesium passage across the blood-brain barrier, raising synaptic magnesium and modulating NMDA receptor activity, density of synapses, and long-term potentiation. Also stabilizes neuronal excitability and supports BDNF expression.

Pharmacokinetics

·
PeakHalf-life
Approximate curve — visual aid only, not data-precise PK

Research Protocols

Disclaimer: These are commonly discussed research protocols and not medical advice.

Goal:Timing — split AM + PM is the default; PM-weighted dosing for sleep-priority users:
Dose:1 cap AM + 2 caps with evening meal) is reported by sleep-priority users to maximize the deep-sleep effect — physiologically plausible given the Mg-GABA-A modulation and the timing of Mg's neuromuscular relaxation effect - All-evening dosing (3 caps with dinner) is the simplest schedule for someone who already takes a separate AM Mg form like glycinate
Frequency:AM
Solo:
Cycle:

Peptide Interactions

magnesium-glycinate / magnesium-bisglycinate (Dylan's V4 pairing):
Synergistic

This is the canonical pairing — Magtein for brain Mg, glycinate/bisglycinate for systemic Mg. Glycinate also brings glycine, a co-agonist at NMDARs and a mil…

citicoline (Dylan's V4):
Synergistic

Both are NMDAR-system modulators — Mg is the channel block, citicoline supports membrane phospholipid substrate (PC) for synaptic membrane integrity. Already…

agmatine:
Synergistic

Mg is voltage-dependent NMDA block; agmatine is a GluN2B-preferential channel modulator with anti-glutamate-excitotoxicity effects. Complementary not redundant.

lithium-orotate (low-dose):
Synergistic

Both are GSK-3β / brain-protection adjuncts at micro-mineral doses; complementary not redundant. Particularly relevant for Dylan's subconcussive-impact conte…

n-acetyl-cysteine:
Synergistic

Glutamate modulation upstream (via system Xc-); complementary to Mg's NMDAR-channel gating.

L-tryptophan / glycine (sleep):
Synergistic

Mg supports sleep architecture; tryptophan/glycine supply substrate for serotonin/melatonin and GABAergic tone.

L-theanine (Dylan's V4 / community-data top pairing):
Synergistic

Theanine modulates GABA and reduces stress-spike cortisol; Mg supports the substrate. Top community combo (253 reports).

DHA / fish oil:
Synergistic

Membrane fluidity + Mg-dependent enzymes both upstream of NMDAR plasticity.

vitamin D3:
Synergistic

Mg is required for the activation of vitamin D (Mg-dependent CYP-mediated 25-hydroxylation in liver). Mg deficiency can blunt the response to vitamin D suppl…

vitamin B6 (P5P):
Synergistic

Mg-B6 synergy is well-documented for sleep + mood — Zhang 2022 RCT formulation explicitly combined them.

High-dose calcium supplements (>1 g/day) at the same dose-time:
Avoid

Compete for absorption at TRPM6/7 transporters; separate by 2 h.

Quinolone (ciprofloxacin, levofloxacin) or tetracycline (doxycycline) antibiotics:
Avoid

Mg chelates and reduces antibiotic absorption ~30-50%; separate by 2-4 h — dose Mg 2 h before or 4-6 h after the antibiotic.

What to Expect

  • Week 1
    Tolerability and dose-response.
  • Week 2-4
    Early effect window.
  • Week 4-8
    Peak benefit assessment.
  • Week 8+
    Cycle decision point.

Side Effects & Safety

  • Common (>10%): Loose stool at >3 g Magtein/day; generally less than Mg oxide or citrate at equivalent elemental doses. Mild GI looseness in the first 3-7 days is typical and resolves.
  • Less common (1-10%):
    • Mild headache during the initial week (Mg-shift-related; resolves with continued use)
    • Vivid dreams or unusually intense dream recall — often welcomed
    • Mild evening sleepiness if dosed in the evening at the higher end (1.5-2 g PM); not problematic for sleep-focused users
    • Mild dizziness or lightheadedness when standing if combined with antihypertensives or in already-low-BP users — Mg modestly lowers BP
  • Rare-serious (<1%):
    • Hypotension at very high Mg doses (>2 g elemental/day) — irrelevant at Magtein practical doses
    • Renal Mg overload only in moderate-to-severe CKD (eGFR <30); contraindicated in dialysis without nephrologist supervision
    • Theoretical: mineral-balance disruption (calcium, potassium) with very prolonged high-dose use — not clinically observed at standard doses
  • Specific watch periods: None unique to Magtein.
  • Pregnancy/breastfeeding: Mg is well-studied and considered safe in pregnancy at RDA-equivalent doses (IV Mg sulfate is routinely used for preeclampsia and preterm labor). However, Magtein specifically lacks pregnancy RCT data; conservative recommendation is to substitute with Mg glycinate during pregnancy, which has more historical use.

References

Lopresti & Smith 2026 — Magtein RCT 18-45 cognitive age + sleep (Frontiers in Nutrition)

pubmed.ncbi.nlm.nih.gov · 2026

n=100, 6 weeks, 2 g/day; 7.5-year cognitive age reduction

View Study

Hausenblas et al. 2024 — MgT Oura-monitored sleep RCT 35-55 (Sleep Medicine: X)

pubmed.ncbi.nlm.nih.gov · 2024

n=80, 21 days, 1 g/day; deep sleep + REM gains

View Study

Hausenblas et al. 2024 corrigendum (Sleep Medicine: X)

pubmed.ncbi.nlm.nih.gov · 2024

minor statistical correction

View Study

Zhang et al. 2022 — Magtein PS-formula cognitive RCT in Chinese adults (Nutrients)

pubmed.ncbi.nlm.nih.gov · 2022

n=109, 30 days; all five WMS subscales improved

View Study

Surman et al. 2021 — Magtein ADHD open-label pilot (J Dietary Supplements)

pubmed.ncbi.nlm.nih.gov · 2021

n=15, 12 weeks; 47% responder rate

View Study
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