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Research pass: medium Compound CONFIRMED-IN-USE HIGH

Magnesium L-Threonate (Magtein)

Extended Research
◈ Extended Research ◈

Our depth — beyond the mirror

Deeper analysis, verdict reasoning, and per-archetype recommendations from our research team.

▸ Our verdict CONFIRMED-IN-USE HIGH

Already locked in Dylan's V4 stack (Source Naturals Magtein, 3 caps/day = ~144 mg elemental Mg as L-threonate). The single magnesium form with credible evidence for raising CSF Mg in humans, with a B-tier human cognitive RCT (Liu 2016) showing memory and executive function improvement in older adults. For a 20yo brain-priority MMA athlete with chronic subconcussive impact exposure, the brain-penetrant Mg angle complements the systemic Mg from Mg glycinate (which Dylan also takes 4 tabs = 400 mg). Maintain current dosing.

Research pass: medium
▸ Decision matrix by user profile Per-archetype
  • Dylan20-30, brain-priority, high cognitive workload (Dylan-archetype)
    STRONG-CANDIDATE

    Brain-penetrant Mg directly supports the brain-protection priority. Synergistic with subconcussive impact context (NMDA-excitotoxicity buffering).

  • 30-50, executive maintenance
    STRONG-CANDIDATE

    Same logic; cognitive maintenance angle.

  • 50+, mild cognitive decline
    STRONG-CANDIDATE

    Liu 2016 trial population. The most evidence-supported use case.

  • Anxiety-prone
    OPTIONAL-ADD

    Mg-anxiolysis broadly true; threonate vs glycinate distinction less material here.

  • High athletic load, tested status
    OPTIONAL-ADD

    as adjunct to systemic Mg (glycinate is cheaper for the athletic Mg-replete goal).

  • Sleep-disordered
    OPTIONAL-ADD

    Glycinate often preferred for sleep specifically.

  • Recovery-focused (post-injury, post-illness)
    STRONG-CANDIDATE

    for post-concussion / TBI recovery — brain-penetrant Mg is the unique tool.

  • Strength/anabolic-focused
    NEUTRAL

    Use cheaper Mg form for systemic repletion.

▸ Subjective experience (deep)
  • Onset: Subtle, over 1-2 weeks of consistent dosing
  • Often imperceptible day-to-day; effect tracked better by retrospective comparison than felt acutely
  • Some report vivid dreams (Mg-typical at adequate replete levels)
  • No "lift" or stimulant feel; this is a structural/baseline tool, not a state-change tool
  • Loose stool risk lower than Mg oxide/citrate at equivalent doses
▸ Tolerance + cycling deep dive
  • Tolerance buildup: None
  • Recommended cycle: None — daily-safe, indefinite
  • Reset protocol: N/A
▸ Stacking deep dive

Synergistic with

  • citicoline: Both NMDA-modulators; Mg is the channel block, citicoline supports membrane substrate. Already paired in V4.
  • agmatine: Mg is voltage-dependent NMDA block; agmatine adds GluN2B-preferential channel block. Clean overlap.
  • lithium-orotate: Both are GSK-3β / brain-protection adjuncts; complementary not redundant
  • n-acetyl-cysteine: Glutamate modulation upstream; complementary
  • L-tryptophan / glycine (sleep): Mg supports sleep architecture; tryptophan/glycine supply substrate for serotonin/melatonin and GABAergic tone
  • DHA / fish oil: Membrane fluidity + Mg-dependent enzymes both upstream

Avoid stacking with

  • High-dose calcium supplements (>1 g/day) at the same dose: Compete for absorption; separate by 2 h
  • Quinolone or tetracycline antibiotics: Mg chelates and reduces antibiotic absorption; separate by 2-4 h

Neutral / safe co-administration

All other V4/V5 stack compounds.

▸ Drug interactions deep dive
  • Quinolone / tetracycline antibiotics: Reduced antibiotic absorption — separate by 2-4 h
  • Bisphosphonates: Reduced bisphosphonate absorption — separate by 2 h
  • Levothyroxine: Reduced absorption — separate by 4 h (rarely relevant at Magtein doses but technically applies)
  • Diuretics (loop, thiazide): Increase urinary Mg loss — may need higher Mg dose
  • PPIs (chronic): Reduce Mg absorption — patients on chronic omeprazole etc. often Mg-deficient
  • CYP enzymes: None — Mg is not a CYP substrate
▸ Pharmacogenomics
  • TRPM6 / TRPM7 variants affect intestinal Mg absorption efficiency — may alter dose required for repletion. Not actionable without genotyping.
  • CNNM2 variants affect renal Mg reabsorption.
  • For Dylan (23andMe pending): If raw data shows TRPM6 reduced-function variants, may benefit from higher total Mg dose. Otherwise, V4 doses are appropriate.
▸ Sourcing deep dive
Path Vendor Cost Reliability Notes
OTC Magtein-licensed Source Naturals (Dylan's V4) $25-30 / 90 caps ($25-30/mo at 3/day) high True licensed Magtein extract; what Dylan is taking
OTC Magtein-licensed Jarrow Magtein ~$25-35 / 90 caps high Equivalent licensed product
OTC Magtein-licensed Doctor's Best, Designs for Health ~$30-40 high Premium positioning
Generic "Mg threonate" Various Amazon brands ~$15-20 low-medium May or may not be licensed Magtein; standardization variable; risk of underdosed product

For Dylan: Source Naturals Magtein in V4 is the optimal pick.

▸ Biomarkers to track (deep)
  • Baseline: RBC magnesium (more accurate than serum); serum Mg; ionized Mg if available
  • During use: RBC Mg at 3-6 months
  • Post-cycle: N/A
▸ Controversies / open debates Live debate
  • Industry funding bias: The Liu 2016 RCT was funded by MagCeutics (Magtein patent holder). Independent replication has been slow.
  • CSF Mg elevation in humans: Slutsky 2010 showed it in rats; equivalent human imaging-based or LP-based confirmation is missing. The animal-to-human translation is plausible but not directly proven.
  • Cost-benefit vs Mg glycinate: Magtein is 5-10× more expensive per elemental Mg gram than glycinate. The premium is for the brain-penetration claim; whether it's worth it depends on whether you value the brain-specific angle vs systemic-Mg-replete-only.
  • Optimal dose: Liu RCT used 1.5-2 g; many users take less for cost reasons. Dose-response curve in humans not characterized.
▸ Verdict change log
  • 2026-05-06 — Initial verdict: CONFIRMED-IN-USE (HIGH confidence). Locked in V4 at 3 caps Source Naturals Magtein/day. Best-evidenced brain-penetrant Mg form; complements V4 Mg glycinate.
▸ Open questions / gaps Open
  • Independent human RCT replication of Liu 2016
  • Human CSF Mg measurement after Magtein loading
  • Head-to-head vs Mg glycinate for cognitive endpoints
  • Whether the L-threonate counter-ion has independent neurotrophic effects beyond its role as a Mg carrier
▸ Sources (full, with our context)
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