Magnesium L-Threonate
Also known as: L-threonic acid magnesium salt
Magnesium L-threonate is a form developed with brain-related research in mind, and it is commonly explored in cognition and evening routines. Human evidence is preliminary, with only small studies so far. Note that its elemental magnesium per dose is low compared with forms like glycinate or citrate, so it is usually chosen for the specific form rather than to correct low magnesium intake.
Snapshot
Evidence level is outcome-specific; a supplement can have stronger evidence for one use and limited evidence for another.
What this page can tell you: Commonly discussed timing, food notes, caution categories, and an honest note on how much source review this entry still needs.
What it cannot: Whether this is appropriate for you personally, or that it treats, prevents, or cures any condition. Informational only — discuss with a clinician or pharmacist.
🕒 Timing
When: Evening, Bedtime
Food: With or without food
Commonly taken in the evening; some study protocols split dosing across the day.
💊 Common use range
1,500–2,000 mg (compound)
Provides relatively little elemental magnesium; still, count total supplemental magnesium across products against commonly cited limits.
Ranges are informational, not a recommended dose. Talk to a professional about what is right for you.
⚠️ Commonly noted interactions (supplements)
Often about absorption or timing rather than danger — separating doses is common. This list is not exhaustive.
🧭 Baseline caution
General caution for ordinary, common use — before accounting for your specific dose, medications, health history, or procedures.
No general caution factors flagged for ordinary use. See context alerts below for situations that may still apply to you.
Caution level is an informational summary of commonly discussed caution categories and doses — not a safety rating, approval, or medical advice. Low caution does not mean safe for you.
🔎 Context alerts to review
Context alerts may matter depending on your dose, medications, health history, or procedure plans — they do not mean the supplement is generally risky at ordinary use.
Dose / upper limit
- Has a commonly discussed upper limit — watch total daily intake
Medications
- Sedating — don't combine with alcohol or sedatives
Spacing & absorption
- Mineral spacing — minerals compete for absorption
Evidence still under review
- Evidence not fully source-reviewed yet
🩺 Medication caution categories
None flagged here, but always review your full routine with a professional.
🏥 Surgery & procedure caution
Not a well-established surgical concern; share your full supplement list with your care team.
If you have a procedure scheduled, bring your full supplement list to your surgical and anesthesia team. Do not stop prescribed medication unless your clinician tells you to. Do not start or stop supplements based only on this app.
✅ Quality checklist
- Prefer products with third-party testing or a certificate of analysis (COA).
- Check the label for the exact form and the elemental or active amount per serving.
🧩 Commonly paired with
🔁 Alternatives
🗣️ Questions for a professional
- Between magnesium forms, does L-threonate make sense for my goals, or is a higher-elemental form more appropriate?
🔬 Evidence snapshot
Magnesium L-threonate is a form marketed for brain/cognition, promoted largely on animal data plus small, short, preliminary human trials — human evidence does not establish a cognitive benefit. General magnesium facts apply: the supplemental Tolerable Upper Intake Level is 350 mg/day of elemental magnesium, and L-threonate delivers relatively little elemental magnesium per dose.
🧪 Forms & quality
Source type: Mineral
L-threonate is magnesium bound to L-threonic acid, a vitamin C metabolite. The elemental magnesium per capsule is typically low, so labels often show both the compound and elemental amounts.
The 'L-' prefix describes the molecule's stereochemical configuration (which mirror-image form it is) — not 'left side' and not a quality grade.
Many biological molecules exist in mirror-image forms (L- and D-). Supplements typically use the form the body recognizes; for threonic acid that is the L-form.
See the supplement glossary for what form names like "L-", chelated, or standardized extract mean.
📏 Dose & monitoring
Needs evidence review — no source-reviewed information yet. We only show dose and monitoring details after they have been checked against reputable sources.
Evidence vs. burden: Not yet reviewed
Labs that may be worth discussing: Electrolytes, Kidney function
These are discussion prompts, not required tests. A healthcare professional can advise what makes sense for you.
😐 Commonly reported side effects
- Drowsiness or headache in some people
- Digestive upset
Non-exhaustive and individual.
🔄 Cycling & breaks
No established cycling pattern.
📅 Daily use notes
Minerals can compete for absorption, so it is commonly spaced away from zinc, iron, and calcium.
📋 Source review status
Partially reviewed — last reviewed 2026-07-12
Partially reviewed 2026-07-12: NIH ODS Magnesium fact sheet (general safety) + a preliminary human trial. Form-specific cognition/sleep evidence is preliminary (small/open-label). Supplemental UL 350 mg/day elemental Mg; diarrhea is the dose-limiting effect; space from bisphosphonates and tetracycline/quinolone antibiotics.
Research backlog (queries to verify):
- magnesium L-threonate cognition human randomized trial
- magnesium L-threonate elemental magnesium content comparison
📚 References
- NIH ODS — Magnesium (Health Professional Fact Sheet)NIH ODS — Supplemental UL 350 mg/day elemental Mg; high doses cause diarrhea/nausea/cramping; space from bisphosphonates and tetracycline/quinolone antibiotics.
- Preliminary trial — magnesium L-threonate & cognitionPubMed review — Open-label, n=15, no placebo control; authors conclude larger placebo-controlled trials are warranted — form-specific cognition evidence is preliminary.
Verified against the source shown. See the research-status page for how review works.
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