Magnesium L-Threonate

Full profile

Evidence, honestly graded

Upgraded from Emerging to C on 2026-09-14. The mechanism rests on rodent work (Slutsky 2010, Neuron). Three small trials built around magnesium L-threonate report benefits, and all three were commercially funded. Liu 2016 (~44 completers, older adults with cognitive complaints) tested MMFS-01, which contains magnesium L-threonate (a salt the authors say they developed), and reported an improvement in overall cognitive ability versus placebo (p = 0.003); Neurocentria funded it, designed it jointly with the contract research site that ran it, analysed the cognitive outcomes and wrote the paper, and the authors report that effects on sleep and anxiety could not be determined. Hausenblas 2024 (80 adults with self-reported sleep problems) reported better sleep quality and daytime functioning; AIDP commissioned and funded it, three of its six authors are paid by AIDP, and a 2025 corrigendum disclosed that the trial was registered retrospectively. Lopresti & Smith 2026 (100 adults aged 18–45 with poor sleep), funded by the ingredient's owner, reported a modest improvement on an overall cognition composite (p = 0.043) and reaction time and better self-rated sleep, but no change on objective sleep measures. Two further trials qualify that picture. Zhang 2022 (109 healthy adults, 30 days) reported memory-test scores significantly higher than placebo (p < 0.001), but it tested a combination formula that also contained phosphatidylserine and vitamins, funded by Wu-xi Magtein Bioscience, so it cannot isolate this ingredient. Ni 2023 randomized 109 patients after breast-cancer surgery to 1.2 g/day magnesium L-threonate (48) or placebo (61) for 12 weeks and found no significant between-group differences in pain, anxiety, depression, sleep or cognition; it reports public funding and no conflicts of interest. That is a clinical population, but the null result comes from outside the commercially funded research. That is enough human signal for C, not B: the positive trials are small and commercially funded, the 2026 trial's results are borderline (p = 0.043 and 0.031), the stronger results come from a developer-funded trial of about 44 people and a formula that cannot isolate the ingredient, the sleep findings are not consistent, and no independent group has replicated the benefits. General magnesium status remains a separate, better-founded topic.

See the full grading rubric (study type, replication, population match, and dose adequacy) in The Evidence Standard.

Side effects

• Generally well tolerated
• Headache or drowsiness reported
• GI upset or loose stools (less than with oxide/citrate)

The full side-effect breakdown: Magnesium L-Threonate Side Effects: What to Know Before You Start.

Who should avoid it or check first

• Kidney impairment (reduced magnesium clearance) without clinician oversight
• Pregnant or breastfeeding without clinician guidance

Interactions

• Can reduce absorption of some antibiotics (tetracyclines, quinolones) and bisphosphonates; separate the doses
• Additive with other magnesium sources; watch total elemental magnesium

Stacks well with

• L-Theanine
• Vitamin D3
• B-Complex (B6, B9, B12)

Use caution stacking with

• Other high-dose magnesium salts (cumulative laxative and elemental load)

What to look for on a label

• Always disclose elemental magnesium per serving, not just the threonate compound weight. The two differ substantially, and this is the most common way this ingredient is oversold.
• Health Canada's magnesium monographs cover mineral/electrolyte, muscle, and bone roles, not cognition. Do not present threonate as a Health-Canada-recognized cognition ingredient, as a brain claim is off-monograph.

References

• Slutsky 2010, Neuron: brain magnesium and memory (preclinical). Rodent study; foundational mechanism, not human proof. PMID 20152124; doi:10.1016/j.neuron.2009.12.026. Educational.
• Liu 2016, J Alzheimers Dis: MMFS-01 human RCT. Small (~44 completers) trial of MMFS-01, which contains magnesium L-threonate (a salt the authors say they developed), in older adults with cognitive complaints. Overall cognitive ability improved versus placebo (p = 0.003). Funded by Neurocentria and designed jointly by Neurocentria and Miami Research Associates, which ran the trial and collected the data; Neurocentria analysed the cognitive and magnesium outcomes and wrote the paper, and three of the five authors list Neurocentria affiliations. The authors report that strong placebo effects meant effects on sleep and anxiety could not be determined. PMID 26519439; doi:10.3233/JAD-150538. Educational, not a product claim.
• Lopresti AL, Smith SJ (2026). Frontiers in Nutrition, 12:1729164Randomized, double-blind, placebo-controlled, n=100 adults aged 18–45 with self-reported sleep dissatisfaction, 6 weeksStudied dose: 2 g dailyGreater improvement than placebo on an overall cognition composite (p = 0.043) and reaction time (p = 0.031); self-rated sleep-related impairment improved, objective sleep measures did not.
• Hausenblas 2024, Sleep Medicine: X (magnesium L-threonate sleep RCT). 80 adults aged 35–55 with self-reported sleep problems took 1 g/day or placebo; improvements in sleep quality and daytime functioning measures were reported. AIDP Inc. commissioned and funded the study and declares that it owns patents; three of the six authors are paid by AIDP (its VP of R&D and two consulting scientists), and the study product (Magtein) was supplied by Threotech. A 2025 corrigendum (doi:10.1016/j.sleepx.2025.100141) supplied the full competing-interest declaration omitted from the paper and disclosed that the trial was registered retrospectively, on 15 April 2024 (ISRCTN14728094); it states the protocol was not changed after the trial began, and it does not revise the results. PMID 39252819. Educational, not a product claim.
• Zhang 2022, Nutrients: Magtein PS formula in healthy adults. Randomized, double-blind, placebo-controlled trial in 109 healthy Chinese adults aged 18–65 for 30 days, reporting memory-test improvements. The product was a combination formula (magnesium L-threonate with phosphatidylserine and vitamins C, D and B6) provided by Magceutics, and the study was funded by Wu-xi Magtein Bioscience, so it cannot isolate magnesium L-threonate. PMID 36558392. Educational, not a product claim.
• Ni 2023, Breast Cancer: Targets and Therapy (magnesium L-threonate after breast-cancer surgery). Randomized, double-blind, placebo-controlled trial in 109 patients: 48 took 1.2 g/day and 61 took placebo for 12 weeks. No significant between-group differences in pain, anxiety, depression, sleep (PSQI) or cognition (TICS). The paper reports funding from the National Natural Science Foundation of China and other public grants, and no conflicts of interest. A clinical population, cited as a null result from outside the commercial research. PMID 37520407. Educational, not a product claim.

Grades and studied doses are our conservative reading of the human research, shown for education. They are not product claims, and a studied dose is not a recommended dose.

Revision history

Every change to this ingredient's evidence status, dated and explained. The full cross-library log lives at Evidence Updates.

• 2026-09-17Citation review

  Funding and conflicts now disclosed for the three positive trials behind this grade: Liu 2016 (funded by Neurocentria, which analysed the cognitive outcomes and wrote the paper), Hausenblas 2024 (commissioned and funded by AIDP Inc., with three of six authors paid by AIDP) and Lopresti & Smith 2026 (funded by the ingredient's owner). A 2025 corrigendum to Hausenblas 2024 supplied its omitted competing-interest declaration and disclosed that the trial was registered retrospectively. Two more trials are now cited: Zhang 2022, a commercially funded combination-formula trial that cannot isolate this ingredient, and Ni 2023, a publicly funded trial after breast-cancer surgery that found no significant difference from placebo in sleep, mood or cognition. The grade is unchanged at C.

• 2026-09-14Grade changeEmerging → Grade C

  Upgraded from Emerging to C. Randomized trials published in 2024 and 2026 reported modest improvements in cognition or self-rated sleep, alongside an earlier small cognition trial, but all three were commercially funded and none has been independently replicated, so it stops at C.

• 2026-07-05New profile

  Initial profile published at Grade Emerging: the mechanism rests on rodent work (Slutsky 2010), with only a small developer-linked human trial to date.

See how Magnesium L-Threonate compares on grade, dose, and goal in the Evidence Explorer.