A reference work, not a recommendation to use: this profile describes mechanism and evidence and does not replace medical advice. The claims come from marketing and forums and are tested here, not endorsed.
Claims checked
Memory ↑, better cognition
Single unconfirmed findingIn healthy people, only one RCT with the salt alone: overall cognitive score just significant (p = 0.043), Raven test without difference, funded by the manufacturer [8]. The larger effect in older adults with complaints comes from a study of 44 people evaluated by the developer [7]; another study tested a mixture [9].
Better sleep
Mixed resultsA distributor study found better tracker values for deep and REM sleep [10]; a manufacturer study found no differences in objective sleep values and only in one of three subjective measures [8]. In the study with older adults, placebo effects precluded a conclusion [7]. No polysomnography.
Stress ↓, less anxiety
Mixed resultsGeneral well-being unchanged, heart rate lowered and heart rate variability raised [8]; better mood scores in the distributor study [10]; anxiety in older adults could not be determined because of placebo effects, although the study was designed for it [7].
Helps with ADHD
Single unconfirmed findingOpen pilot study without a control group, 15 people, 47% met the responder criteria [11].
small studies: Every study behind this level and result had fewer than 100 participants. Small studies report larger effects on average than large ones, so the result is less certain.
manufacturer-funded: According to their funding or competing-interest statements, all studies behind this result were paid for, wholly or in part, by the maker of the product or compound, or list employees of the maker among their authors. Manufacturer-funded studies on average come out more favourably for the product.
Mechanism of action
Evidence map: Magnesium L-threonate
Magnesium is involved in more than 600 enzymatic reactions; the gut, kidney and bone regulate its levels [1]. In nerve cells, Mg2+ blocks the NMDA receptor channel in a voltage-dependent manner [2]. Magnesium L-threonate (L-TAMS, trade name Magtein) combines magnesium with L-threonic acid; the compound was deliberately developed by the group around G. Liu to raise magnesium in the brain [3].
In rats, magnesium L-threonate improved learning as well as working, short-term and long-term memory, and increased the density of presynaptic markers in the hippocampus and the amount of NR2B-containing NMDA receptors [3]. In that work, magnesium in the cerebrospinal fluid rose by about 7% compared with baseline after 24 days and by 16% compared with a control group whose values fell because of the sampling, as EFSA summarizes [4]. In nerve cell cultures, threonate itself raised the intracellular magnesium concentration, mediated by glucose transporters; other magnesium anions did not do this [5]. An independent group found more magnesium in the cerebrospinal fluid of mice after magnesium L-threonate, but not after magnesium sulfate [6]. In humans, magnesium in cerebrospinal fluid or brain has never been measured after intake.
How well magnesium from this form is absorbed compared with other salts has not been studied in humans. EFSA based its assessment on a dissolution experiment, two rat studies and one human study; in an unpublished rat study by the applicant, relative absorption was about 60% compared with 40–45% for chloride, gluconate and citrate [4]. In the human study, urinary magnesium rose by 41% after 12 weeks compared with 8% under placebo, plasma only significantly after 6 weeks, and erythrocyte magnesium not at all [4]. EFSA concluded that magnesium is available from this source; it did not establish superiority over other forms [4].
All randomized human studies were funded by manufacturers or distributors. In 44 evaluated 50- to 70-year-olds with memory complaints, a product containing L-TAMS improved an overall cognitive score (d = 0.91); the company Neurocentria funded the study, evaluated the cognitive tests itself and wrote the publication, and the sample size was designed for an anxiety endpoint whose effect could not be determined because of strong placebo effects [7]. In 100 adults (18–45 years) with dissatisfying sleep, an overall cognitive score rose just significantly (p = 0.043), the Raven test did not; objective sleep values from the tracker did not change (funded by Threotech) [8]. A study of 109 healthy people tested a mixture with phosphatidylserine and vitamins, so the effect cannot be attributed to the magnesium salt (funded by a Magtein manufacturer) [9]. A study with 80 adults, funded and co-authored by the distributor AIDP, found better values for deep and REM sleep with a finger-ring tracker [10]; an open pilot study of 15 adults with ADHD without a control group reported improvements [11].
Synaptik serves solely to explain biochemistry and pharmacology and is not medical advice or a recommendation to take anything.
Glutamate Glycine / D-serine Mg²⁺ Ca²⁺ Na⁺ K⁺ red = drug, shown in the scene as a miniature skeletal formula · shapes as in the figure
Baseline
Ca²⁺ influx (model): baseline
Magnesium L-threonate
Ca²⁺ influx (model): unchanged
The left panel runs at baseline, the right one with the selected drug, both with the same beats. The word and bar under the panels show, without a number, only the direction (less or more Ca²⁺ than at baseline). The model is illustrative, not a measurement, and says nothing about the size of the effect in the brain.
Magnesium L-threonate was developed to raise magnesium in the brain. In rats, CSF magnesium rose and the hippocampus contained more NR2B (GluN2B)-containing NMDA receptors [15]; brain or CSF magnesium has never been measured in humans. At the channel itself the Mg²⁺ ion acts as it does from any salt: voltage-dependent block [3]. Mg²⁺ and GluN2B are highlighted; the model stays at baseline.
Tap or focus a labelled part for a one-line explanation.
Also acting here, not drawn
- CX-717: ampakine; NMDA effect only indirect, no action on the receptor itself
- Huperzine A: NMDA inhibition only in a review by the developers’ group, without a binding site
- L-theanine: only very weak binding to glutamate receptors
- Phenylpiracetam: no displacement of ligands at NMDA receptors
- Piracetam: only changed receptor numbers (mice)
- Selank: only changed numbers of binding sites (mice)
Targets
| Target | Type | Action | Key data | Evidence |
|---|---|---|---|---|
| NMDA receptor, channel pore | Ion channel | Inhibitor | voltage-dependent block by Mg2+ (mouse neurons) | Laboratory[2] |
| NR2B-containing NMDA receptors | Receptor | Expression ↑ | rat hippocampus; neuron culture | Animal study[3][5] |
| Glucose transporter (GLUT), threonate uptake | Transporter | Binding | mediates the threonate effect on intracellular Mg2+ (cell culture) | Laboratory[5] |
Effect profile
- Dopamine
- Noradrenaline
- Serotonin
- Acetylcholine
- Glutamate · AMPA
- Glutamate · NMDAMg2+ block of the NMDA channel (laboratory); NR2B-containing NMDA receptors and synapse density increased (rat, cell culture, developer group)[2][3][5]
- GABA
- Histamine
- Orexin
- Adenosine
- Opioids
- Melatonin
- Neurotrophins
- Blood flow
- Nitric oxide
- Energy metabolismMitochondrial membrane potential increased in neuron culture[5]
- Insulin · glucose
- Inflammation · oxidative
- Stress axis
- Testosterone axis
- Endocannabinoids
- Autophagy · senescence
- Immune system
- Lipid metabolism
- Coagulation · fibrinolysis
- Methylation
Routes of administration and bioavailability
Oral (swallowed) · L-Threonate (Magtein)
not quantified in humansIn the only human study with status measurement, urinary magnesium rose by 41% after 12 weeks (placebo 8%), plasma only significantly after 6 weeks, erythrocytes not [4]. No human comparison with other salts.
Human, randomised
Oral (swallowed) · L-Threonate, animal data
≈ 60% relative absorption (rat; chloride, gluconate, citrate 40–45%)Unpublished study by the applicant, summarized by EFSA [4]; cerebrospinal fluid magnesium raised in rats and mice [3][4][6].[3][6]
Animal study
Human studies
Cognition in older adults with memory complaints (MMFS-01)
Measured: overall cognitive score from four domains
Result: Better than placebo (p = 0.003, d = 0.91); sleep and anxiety could not be determined because of placebo effects.[7]
Human, randomised
Cognition and sleep in young adults
Measured: NIH Toolbox overall cognition, Raven, sleep questionnaires, Oura ring
Result: Overall cognition p = 0.043, Raven p = 0.953; one sleep measure better (p = 0.043), objective sleep values without difference.[8]
Human, randomised
Mixed product with phosphatidylserine
Measured: Clinical Memory Test
Result: All five subtests better than placebo; effect cannot be attributed to the magnesium salt.[9]
Human, randomised
Sleep in adults with sleep problems
Measured: Sleep questionnaires, Oura ring
Result: Better tracker values for deep and REM sleep as well as subjective daytime well-being.[10]
Human, randomised
ADHD pilot study
Measured: AISRS, CGI-I
Result: 47% responders; improvements in AISRS and CGI-I.[11]
Human, non-randomised
Risks and warnings
Safety assessment
EFSA considers the salt safe under the conditions applied for; the application excluded pregnant and breastfeeding women, and the authorization prescribes a corresponding statement [15]. The product may contain up to 1% oxalic acid, which EFSA classified as of no concern [4]. Gastrointestinal complaints were not more frequent than under placebo in the study with older adults (20.0 vs. 15.4%) [7].
Human, randomised
Hypermagnesemia in impaired kidney function
The kidney regulates the magnesium balance [1]; in a cohort receiving magnesium oxide, impaired kidney function, larger amounts and longer use were risk factors for elevated values [12]. Data on L-threonate are lacking; the transfer is an inference.
Human, non-randomised
Interactions
- Tetracyclines and fluoroquinolones: Polyvalent cations such as Mg2+ form chelates with these antibiotics and reduce their absorption; shown for magnesium-containing antacids [13]. Not studied specifically for L-threonate.
- Bisphosphonates: Same chelate mechanism according to prescribing information, quantitative data lacking [13].
Fact check: common claims
- not supported
“Magnesium L-threonate is the only form of magnesium that reaches the brain”
Cerebrospinal fluid magnesium rose by about 7% above baseline in rats [3][4] and in mice compared with magnesium sulfate [6]. In humans, there is no measurement in cerebrospinal fluid or brain, and most other forms were never compared.
- not supported
“Magtein makes the brain about nine years younger”
The “brain age” was estimated from the speed in a single test (Trail Making Test B) compared with normative values, in a study of 44 people evaluated by the manufacturer [7]; the second study reports an estimated cognitive age, likewise funded by the manufacturer [8].
- partly supported
“The effect on memory is clinically proven”
Two manufacturer-funded RCTs with the salt show improvements, in young adults only just significant and not in the Raven test [7][8]; the third tested a mixture [9]. Independent confirmation is lacking.
- not supported
“Magnesium L-threonate improves deep sleep”
Only tracker estimates, no polysomnography; positive in one distributor study [10], without difference in one manufacturer study [8].
- partly supported
“The threonate itself is decisive for the effect”
In neuron cultures, only threonate raised intracellular magnesium, not other anions [5]; data from the developer group, untested in humans.
Pharmacokinetics
- Absorption
- By mouth; magnesium available from it, judged by rising urinary excretion (one study) [4].
- Half-life
- Threonate moiety: plasma half-life about 2.5 hours after calcium L-threonate in humans, according to EFSA [4]. Cannot meaningfully be stated for magnesium.
- Metabolism
- L-Threonic acid is also formed during the breakdown of vitamin C; its further metabolism in humans has hardly been studied [4].
- Entry into the brain
- Cerebrospinal fluid magnesium about 7% above baseline in rats [3][4], raised in mice [6]; threonate in the cerebrospinal fluid of rats raised [5]. Not measured in humans.
Legal status
- Germany
- No marketable medicinal product for human use containing magnesium L-threonate as the active substance was found in AMIce (search by substance name, retrieved October 24, 2026) [17]; as a mineral compound under Annex II of Directive 2002/46/EC, it is permitted in food supplements [14].
- EU
- Annex II Part B of Directive 2002/46/EC (“magnesium L-threonate,” with a reference to the Union list) [14]. In the Union list of novel foods, authorized on November 7, 2024 for food supplements for adults, excluding pregnant and breastfeeding women, with a corresponding mandatory statement; applicant AIDP Inc., data protection until November 7, 2029 [15]. The basis was the EFSA assessment of 2024 (safe, magnesium available from it) [4].
- USA
- According to the study authors, GRAS status (“self-affirmed/FDA-affirmed”) [7]; not independently checked.
Authorised EU health claims
“contributes to normal psychological function”
- Nutrient
- Magnesium
- Legal basis
- Regulation (EU) No 432/2012[16]
- Reading
- legally permitted for magnesium in general, no statement about magnesium L-threonate; for cognition, see the promise “Memory ↑, better cognition” (single unconfirmed finding)
Related compounds
Open questions
- Does magnesium in human cerebrospinal fluid rise more after magnesium L-threonate than after other salts?
- Do independently funded, preregistered studies confirm the cognitive effects?
- How does absorption in humans compare directly with citrate or glycinate?
References
- de Baaij JH, Hoenderop JG, Bindels RJ. Magnesium in man: implications for health and disease. Physiol Rev. 2015;95(1):1–46. doi:10.1152/physrev.00012.2014 · PubMed
- Nowak L, Bregestovski P, Ascher P, Herbet A, Prochiantz A. Magnesium gates glutamate-activated channels in mouse central neurones. Nature. 1984;307(5950):462–5. doi:10.1038/307462a0 · PubMed
- Slutsky I, Abumaria N, Wu LJ, Huang C, Zhang L, Li B, et al. Enhancement of learning and memory by elevating brain magnesium. Neuron. 2010;65(2):165–77. doi:10.1016/j.neuron.2009.12.026 · PubMed
- EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA); Turck D, Bohn T, Castenmiller J, De Henauw S, Hirsch-Ernst KI, et al. Safety of magnesium L-threonate as a novel food pursuant to regulation (EU) 2015/2283 and bioavailability of magnesium from this source in the context of Directive 2002/46/EC. EFSA J. 2024;22(3):e8656. doi:10.2903/j.efsa.2024.8656 · PubMed
- Sun Q, Weinger JG, Mao F, Liu G. Regulation of structural and functional synapse density by L-threonate through modulation of intraneuronal magnesium concentration. Neuropharmacology. 2016;108:426–39. doi:10.1016/j.neuropharm.2016.05.006 · PubMed
- Shen Y, Dai L, Tian H, Xu R, Li F, Li Z, et al. Treatment of magnesium-L-threonate elevates the magnesium level in the cerebrospinal fluid and attenuates motor deficits and dopamine neuron loss in a mouse model of Parkinson's disease. Neuropsychiatr Dis Treat. 2019;15:3143–53. doi:10.2147/NDT.S230688 · PubMed
- Liu G, Weinger JG, Lu ZL, Xue F, Sadeghpour S. Efficacy and safety of MMFS-01, a synapse density enhancer, for treating cognitive impairment in older adults: a randomized, double-blind, placebo-controlled trial. J Alzheimers Dis. 2016;49(4):971–90. doi:10.3233/JAD-150538 · PubMed
- Lopresti AL, Smith SJ. The effects of magnesium L-threonate (Magtein) on cognitive performance and sleep quality in adults: a randomised, double-blind, placebo-controlled trial. Front Nutr. 2026;12:1729164. doi:10.3389/fnut.2025.1729164 · PubMed
- Zhang C, Hu Q, Li S, Dai F, Qian W, Hewlings S, et al. A Magtein, magnesium L-threonate, -based formula improves brain cognitive functions in healthy Chinese adults. Nutrients. 2022;14(24):5235. doi:10.3390/nu14245235 · PubMed
- Hausenblas HA, Lynch T, Hooper S, Shrestha A, Rosendale D, Gu J. Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: a randomized controlled trial. Sleep Med X. 2024;8:100121. doi:10.1016/j.sleepx.2024.100121 · PubMed
- Surman C, Vaudreuil C, Boland H, Rhodewalt L, DiSalvo M, Biederman J. L-threonic acid magnesium salt supplementation in ADHD: an open-label pilot study. J Diet Suppl. 2021;18(2):119–31. doi:10.1080/19390211.2020.1731044 · PubMed
- Wakai E, Ikemura K, Sugimoto H, Iwamoto T, Okuda M. Risk factors for the development of hypermagnesemia in patients prescribed magnesium oxide: a retrospective cohort study. J Pharm Health Care Sci. 2019;5:4. doi:10.1186/s40780-019-0133-7 · PubMed
- Ogawa R, Echizen H. Clinically significant drug interactions with antacids: an update. Drugs. 2011;71(14):1839–64. doi:10.2165/11593990-000000000-00000 · PubMed
- Richtlinie 2002/46/EG des Europäischen Parlaments und des Rates vom 10. Juni 2002 zur Angleichung der Rechtsvorschriften der Mitgliedstaaten über Nahrungsergänzungsmittel. ABl. L 183 vom 12.7.2002, S. 51. Konsolidierte Fassung vom 26.11.2025 (CELEX 02002L0046-20251126).
- Durchführungsverordnung (EU) 2017/2470 der Kommission vom 20. Dezember 2017 zur Erstellung der Unionsliste der neuartigen Lebensmittel gemäß der Verordnung (EU) 2015/2283 des Europäischen Parlaments und des Rates über neuartige Lebensmittel. ABl. L 351 vom 30.12.2017, S. 72. Konsolidierte Fassung vom 10.08.2026 (CELEX 02017R2470-20260810).
- Verordnung (EU) Nr. 432/2012 der Kommission vom 16. Mai 2012 zur Festlegung einer Liste zulässiger anderer gesundheitsbezogener Angaben über Lebensmittel als Angaben über die Reduzierung eines Krankheitsrisikos sowie die Entwicklung und die Gesundheit von Kindern. ABl. L 136 vom 25.5.2012, S. 1. Konsolidierte Fassung vom 20.08.2025 (CELEX 02012R0432-20250820).
- Bundesinstitut für Arzneimittel und Medizinprodukte. AMIce – Arzneimittel-Informationssystem, öffentlicher Teil [Datenbank]. Suche Stoffname „Magnesium-L-threonat“ [zitiert 24.10.2026]. Verfügbar unter: https://portal.bfarm.de/amguifree/
How this profile was checked
Last reviewed: 2026-10-24. All sources with a DOI or PMID were resolved automatically via Crossref or doi.org and PubMed.
Translated from the German profile (version of 2026-10-24); translation checked on 2026-10-26.
Checked
- DOIs via Crossref and PMIDs via PubMed (checking script).
- Checked against the abstracts: learning, memory, NR2B, synapse markers in rats [3]; threonate via GLUTs, other anions without effect [5]; cerebrospinal fluid magnesium in mice after MgT, not after sulfate [6]; 23 vs. 21 people, p = 0.003, d = 0.91, sleep and anxiety not determinable [7]; 100 people, p = 0.043, Raven p = 0.953, sleep measures, HR p = 0.030, HRV p = 0.036, funding Threotech [8]; 109 people, mixed product [9]; 80 people, Oura ring, AIDP authorship [10]; 15 people, 47% responders [11].
- In the EFSA full text [4]: cerebrospinal fluid +7% vs. baseline and +16% vs. control (rat, after Slutsky 2010); relative absorption ≈ 60% vs. 40–45% (unpublished, applicant); human study urine +41% vs. +8% (p = 0.048), plasma week 6 +4.9% vs. −0.1% (p = 0.026), week 12 not significant, erythrocytes not significant; oxalic acid up to 1%; threonate half-life ≈ 2.5 h (calcium L-threonate).
- In the full text [7]: funding by Neurocentria, cognitive statistics and manuscript by Neurocentria, sample size calculated for HAM-A, “brain age” from TMT-B normative values (9.4 years), GRAS wording, gastrointestinal side effects 20.0 vs. 15.4%.
- In the full text [9]: funding by Wu-xi Magtein Bioscience; [10]: funding by AIDP, three authors employed at AIDP.
- ClinicalTrials.gov: 13 hits for “magnesium threonate” (October 23, 2026).
- October 24, 2026 (rule decisions K1–K8): Annex II Part B of Directive 2002/46/EC (CELEX 02002L0046-20251126, Cellar XHTML) contains “magnesium L-threonate” with a footnote “As listed in the Union list …”. Union list (CELEX 02017R2470-20260810, Cellar XHTML): entry “magnesium L-threonate,” authorized on November 7, 2024, food supplements for adults excluding pregnant and breastfeeding women, mandatory statement, applicant AIDP Inc., data protection until November 7, 2029 (the maximum amount stated there is deliberately not included). Wording “Magnesium contributes to normal psychological function” in Regulation (EU) No 432/2012 (CELEX 32012R0432 and 02012R0432-20250820) found unchanged.
- Conflicts of interest (G9): the “manufacturer-dependent data situation,” previously listed as a separate risk, has been deleted; the declared funding remains in the text, in the study list and under “geprueft.”
- Legal status (G6) on October 24, 2026: AMIce (public part, BfArM; substance name “Magnesium-L-threonat,” active substance only, human medicinal product, marketable): no hits [17]. Without front masking and with differing substance names, this is not proof that no medicinal product exists.
- Precision flags (m004, implemented by Claude on October 26, 2026, for confirmation by Tilman): “Memory ↑, better cognition” → “herstellerfinanziert”: [8] funded according to the funding and conflict-of-interest statement by Threotech Inc., which also supplied the study product (Magtein); [7] according to the full text funded by Neurocentria, co-planned, partly evaluated and written (study product MMFS-01); [9] tested a mixture and does not count.
- Precision flags (m004, implemented by Claude on October 26, 2026, for confirmation by Tilman): “Helps with ADHD” → “kleine_studien”: [11] n = 15 (abstract).
Not verified
No dosages, no sources of supply. This information does not replace medical advice.
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