Adrian L Lopresti, Stephen J Smith
Journal: Frontiers in nutrition 2026;12():1729164
PMID: 41601871
Sleep problems are common in adults and can affect memory, concentration, and overall mental performance. Magnesium plays an important role in brain function and sleep regulation. Magnesium L-threonate (Magtein®) is a form of magnesium that is believed to cross into the brain more effectively than other forms. This study was carried out to determine whether magnesium L-threonate could improve cognitive performance and sleep quality in adults who reported poor sleep.
The results showed that participants taking magnesium L-threonate experienced improvements in some measures of cognitive performance and reported better sleep quality compared to the placebo group. Improvements were particularly noted in areas related to memory and executive function.
In conclusion, magnesium L-threonate supplementation may support cognitive function and sleep quality in adults with sleep dissatisfaction. However, further research is needed to confirm these findings in larger and more diverse populations. Healthcare professionals may consider this evidence when evaluating magnesium supplementation as part of a broader strategy for managing sleep concerns and cognitive performance.
None
•Magnesium threonate is a safe and effective form of magnesium.
• Supplementing with 2g Magtein® (145mg of elemental magnesium) daily improved cognitive function and performance, perceived sleep quality and improved HRV during sleep suggesting potential benefits for improved recovery and reduced stress.
Introduction:
Cognitive impairment, reduced cognitive performance and Alzheimer’s disease have been associated with insufficient blood magnesium levels. Conversely higher magnesium intake has been associated with increased cognitive scores.
Animal studies have demonstrated that magnesium threonate has superior bioavailability and capacity to increase brain concentrations compared to other forms. This study aimed to analyse the effects of 6 weeks of magnesium threonate supplementation (Magtein®) on cognition and sleep in young to middle aged adults with disturbed sleep.
Methods:
• Study design = a, two-arm, parallel-group, randomised, double-blind, placebo-controlled trial (n= 100 male and female adults aged between 18 and 45yrs).
• Participants completed baseline cognitive performance tests (National Institute of Health (NIH) toolbox cognition battery, Raven’s progressive matrices second edition (Raven’s 2) and 3D aim trainer (used to measure hand-eye coordination)), self-reported questionnaires (PROMIS sleep disturbance and sleep-related impairment scale, Restorative sleep questionnaire and World Health Organisation-5 wellbeing index) and were provided an Oura Ring, a smart ring ring that tracks sleep, activity, recovery, heart rate, temperature, and stress.
• Participants were required to begin daily supplementation of either 1g of Magtein® in the morning and evening (145mg of elemental magnesium) or placebo (rice flour) for 6 weeks.
• In person assessments and questionnaires were completed one week prior to commencement and on day 42 following supplementation. Questionnaires were also completed online on days 14 and 28.
Results:
•The intervention group demonstrated a greater increase in the NIH total cognition composition score (8.40 points vs. 5.60 points, p < 0.001 for both).
• The Magtein® group were 2.24 points higher (p = 0.041) in the Total Cognitive Composite Scores at 6 weeks, suggesting an estimated 7.5 year reduction in brain cognitive age.
• The Magtein® group demonstrated improvements of 3.59 points in the aim trainer score (p = 0.009), while the placebo group saw no statistically significant change.
• The Magtein® group experienced a 6.35 point reduction (p < 0.001) in sleep related impairment compared to a 3.38 reduction in the placebo group (p = 0.001).
• There were no statistically significant improvements in the Oura Ring’s sleep data.
• During sleep the intervention group had a lower average heart rate (p = 0.030) and increased HRV (p = 0.036) compared to the placebo.
Conclusion:
Supplementation of Magtein® at 1g twice daily resulted in improvements in overall cognitive performance and subjective sleep compared to the placebo.
Supplementing with 2g Magtein® (145mg of elemental magnesium) daily for six weeks may result in:
• Improvements in cognitive performance.
• A reduction in cognitive age.
• Improved reaction time.
• Reduced heart rate and increased HRV during sleep.
• Improvements to subjective sleep measures.
There were no significant between-group differences in the frequency of adverse events suggesting that Magtein® was safe and well tolerated.
• The present study assessed the effects of magnesium threonate on cognition in young to middle aged adults. Further studies investigating the impact in older adults and those with cognitive decline may offer insight into its potential benefits within these populations.
The study duration was only six weeks. Further studies are needed to identify if the benefits will increase over longer durations.
• The study utilised only a single form of magnesium (magnesium threonate). Further studies comparing different forms and/or combined forms of magnesium on cognition and sleep may offer insight into which form is superior across these measures.
BACKGROUND/OBJECTIVES
Magnesium may help support cognition and sleep. The purpose of this two-arm, 6-week, parallel-group, randomised, double-blind, placebo-controlled trial was to examine the effects of magnesium L-threonate (Magtein®) supplementation on cognitive performance, cognitive age, sleep quality, and selected physiological indicators in adults.
METHODS
One hundred adults aged 18 to 45 with self-reported dissatisfied sleep were supplemented with 2 g daily of Magtein® or a placebo. Outcome measures comprised the computer-based National Institute for Health (NIH) Cognitive Toolbox and Raven's Progressive Matrices Version 2 for the assessment of cognitive function, self-report evaluations of sleep quality and emotional wellbeing, a reaction time test, and physiological data obtained from a sleep-tracking wearable device (Oura Ring), including resting heart rate (HR) and heart rate variability (HRV) during sleep.
RESULTS
Compared to the placebo, Magtein® was associated with greater improvements in overall cognitive performance as measured by the NIH Total Cognition Composite (p = 0.043), with larger treatment effects on working and episodic memory. There was also a 7.5-year reduction in estimated brain cognitive age and a greater improvement in reaction time (p = 0.031). However, there were no group differences in changes in the Raven's test (p = 0.953). Based on self-report measures, there was a greater improvement in sleep-related impairment (p = 0.043), but no group differences in changes in sleep disturbances (p = 0.316), restorative sleep (p = 0.439), or general wellbeing (p = 0.436); although in a subset of participants with more severe sleep-related problems, group differences in sleep-disturbances were identified (p = 0.031). Based on data from the sleep tracking ring, there were no group differences in sleep outcomes, although there was a greater reduction in HR (p = 0.030) and an increase in HRV (p = 0.036), a physiological marker of stress reduction and improved autonomic balance. Magtein® was well-tolerated, and there were no reports of significant adverse reactions.
CONCLUSION
The results from this study suggest Magtein® supplementation for 6 weeks improves overall cognition, cognitive age, working memory, reaction time, HR, HRV, and some subjective, but not objective measures of sleep in healthy adults with self-reported dissatisfied sleep.
Copyright © 2026 Lopresti and Smith.
© Copyright 2026, Nutrition Evidence
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