Magnesium L-Threonate
Also known as: magnesium L-threonate, Magtein®, Magtein®PS, L-TAMS
Human randomised trials show mixed evidence. A 30‑day trial of a Magtein®‑containing formula reported improved memory scores in healthy adults, but the product contained phosphatidylserine and vitamins so effects cannot be attributed to magnesium L‑threonate alone. A randomised trial in people with advanced cancer reported opioid‑sparing effects and reduced opioid‑induced constipation with oral magnesium L‑threonate (1.5–2 g/day). A small crossover trial in XMEN disease showed no benefit and the broader in‑vitro and clinical program was stopped.
Last reviewed: 2026-10-14 · 3 indexed studies
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Overview
Magnesium L‑threonate is a specialised magnesium salt developed to increase magnesium concentrations in the brain. It is marketed for cognitive support and is sold in capsule forms, sometimes combined with other nutrients such as phosphatidylserine and vitamins.
Mechanism & Function
Mechanism of Action
Described in the literature as a magnesium salt that raises brain and neuronal magnesium concentrations more effectively than some other magnesium compounds; increased neuronal magnesium is proposed to support neuronal function and cognition.
Physiological Role
Provides bioavailable magnesium with preferential penetration into brain tissue according to preclinical and the described development rationale; magnesium is an essential cofactor for multiple neuronal processes.
Primary Pathways
Performance / Health Relevance
May support cognitive performance in some populations and appears to have opioid‑sparing effects in a trial of advanced cancer patients. Evidence is limited and sometimes confounded by multi‑ingredient formulations or small sample sizes.
Evidence Review
No meta-analyses or systematic reviews indexed for this ingredient yet.
Dimensions marked N/A have no indexed evidence of that class. They are shown as unavailable rather than scored.
Compare Magnesium Forms
Full comparison5 magnesium forms are indexed. Bioavailability, clinical evidence, and best-use cases differ meaningfully between them.
| Form | Evidence |
|---|---|
Magnesium L-ThreonateThis page Described by the developers and trial abstracts as having superior ability to raise brain magnesium concentrations compared with other magnesium salts. | 54/100 |
| Magnesium Glycinate Glycinate chelation provides ~80% relative bioavailability vs ~4% for magnesium oxide. | 84/100 |
| Magnesium Citrate ~25–30% absorption — superior to oxide; below glycinate for neurological endpoints. | 70/100 |
| Aquamin Mg Comparable to other Mg hydroxide forms. | 58/100 |
| Magnesium Oxide In patients with marked intestinal malabsorption (ileal resection), magnesium oxide showed lower absorption compared with a magnesium diglycinate chelate in a crossover study (7815675). | 52/100 |
Practical Use & Dosage
- Minimum Effective Dose
- Approximately 1.5 g/day (as used in trials)
- Optimal Range
- 1.5–2.0 g/day (doses seen in the reported RCTs)
- Upper / Caution Level
- Not established from the provided abstracts
- Timing
- Not established
- Best Format
- Oral capsules
- Bioavailability
- Described by the developers and trial abstracts as having superior ability to raise brain magnesium concentrations compared with other magnesium salts.
- Absorption Considerations
- Formulation claims higher brain uptake; other absorption modifiers not reported in the provided abstracts.
Safety & Interactions
Side Effects
- •No consistent safety signals reported in the provided oral trials; one trial reported reduced opioid‑induced constipation when used adjunctively
- •Asymptomatic liver enzyme elevation was reported during an IV magnesium phase in one small trial arm (not with oral magnesium L‑threonate in the reported oral phase)
Drug Interactions
- •May reduce opioid requirements when used adjunctively (reported in one trial); clinical implications require monitoring.
Who Should Avoid
- •Insufficient evidence to recommend for children or pregnant/breastfeeding women based on the provided abstracts
- •Patients with specific disorders should consult clinical advice; XMEN disease did not benefit in a small trial
Monitoring
Monitor symptoms and medication requirements when used in patients taking opioids; standard clinical monitoring for magnesium supplements in people with renal impairment is prudent though not reported in these abstracts.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Magnesium L-Threonate typically used or indicated?
Magnesium L-Threonate is most commonly used for: Cognitive support, Memory, Adjunctive analgesia/opioid-sparing in cancer pain. Provides bioavailable magnesium with preferential penetration into brain tissue according to preclinical and the described development rationale; magnesium is an essential cofactor for multiple neuronal processes.
How does Magnesium L-Threonate work?
Described in the literature as a magnesium salt that raises brain and neuronal magnesium concentrations more effectively than some other magnesium compounds; increased neuronal magnesium is proposed to support neuronal function and cognition.
What is the recommended dose of Magnesium L-Threonate?
The optimal range is 1.5–2.0 g/day (doses seen in the reported RCTs). with a minimum effective dose of Approximately 1.5 g/day (as used in trials). Best taken: Not established. Upper / caution level: Not established from the provided abstracts.
What are the side effects of Magnesium L-Threonate?
Reported side effects include: No consistent safety signals reported in the provided oral trials; one trial reported reduced opioid‑induced constipation when used adjunctively; and Asymptomatic liver enzyme elevation was reported during an IV magnesium phase in one small trial arm (not with oral magnesium L‑threonate in the reported oral phase). Monitoring: Monitor symptoms and medication requirements when used in patients taking opioids; standard clinical monitoring for magnesium supplements in people with renal impairment is prudent though not reported in these abstracts.
Does Magnesium L-Threonate interact with medications?
Known or theoretical interactions: May reduce opioid requirements when used adjunctively (reported in one trial); clinical implications require monitoring.. Always check with a clinician before combining with prescription medication.
Who should avoid Magnesium L-Threonate?
Magnesium L-Threonate is generally not recommended for: Insufficient evidence to recommend for children or pregnant/breastfeeding women based on the provided abstracts; and Patients with specific disorders should consult clinical advice; XMEN disease did not benefit in a small trial.
How strong is the evidence for Magnesium L-Threonate?
Evidence level: Limited (overall score 54/100), based on 3 indexed studies on SuppIndex.
Research & References (3)
A Magtein®, Magnesium L-Threonate, -Based Formula Improves Brain Cognitive Functions in Healthy Chinese Adults.
Double‑blind, placebo‑controlled trial in 109 healthy Chinese adults (18–65 y) testing a Magtein®PS formulation (magnesium L‑threonate + phosphatidylserine + vitamins C and D) 2 g/day for 30 days using the Clinical Memory Test.
A Double-Blind, Placebo-Controlled, Crossover Study of Magnesium Supplementation in Patients with XMEN Disease.
Randomized, double‑blind, placebo‑controlled, crossover study of oral magnesium L‑threonate in patients with XMEN disease (part 1: 12 weeks on either treatment then crossover). Small sample; in vitro supplementation experiments also performed.
Oral application of magnesium-L-threonate enhances analgesia and reduces the dosage of opioids needed in advanced cancer patients-A randomized, double-blind, placebo-controlled trial.
Prospective, randomized, double‑blind, placebo‑controlled trial in advanced cancer patients taking oral opioids, assigned to oral magnesium L‑threonate (L‑TAMS) capsules (1.5 g or 2.0 g according to weight) or placebo, with morphine dose tracked over 90 days.
Related Ingredients
Other top-rated ingredients in Minerals.
Magnesium Glycinate
84/100An amino acid chelate of magnesium providing elemental Mg²⁺ bound to two glycine molecules, offering superior bioavailability and minimal gastrointestinal side effects.
Calcium Citrate
75/100Calcium bound to citric acid; ~24% elemental Ca by mass; absorbed across the small intestine via active transport and paracellular diffusion regardless of gastric pH.
Zinc
74/100Systematic reviews and meta-analyses of human trials show that oral zinc supplementation reduces duration and increases recovery rates in acute and persistent watery diarrhoea in children; lowers inflammatory lesion counts in acne; reduces pain severity in primary dysmenorrhea; and in small trials (20–30 mg/day) improved fasting glucose and 2‑hr OGTT in people with prediabetes. Adverse effects reported include increased vomiting in children receiving zinc for diarrhoea.
Research Overview
Limited EvidenceCite this ingredient
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Stable URL
https://thesuppindex.com/ingredients/magnesium-l-threonate
SuppIndex. (2026). Magnesium L-Threonate: Evidence summary, dosage and clinical studies. Retrieved October 16, 2026, from https://thesuppindex.com/ingredients/magnesium-l-threonate
Based on 3 indexed studies · Evidence level: Limited.
Goal Ratings
Stack Compatibility
Often combined with phosphatidylserine and vitamins in studied formulations; effects observed in multi‑ingredient products cannot be attributed to magnesium L‑threonate alone.