A new randomized, double-blind, placebo-controlled clinical trial found that 2g daily supplementation with Magtein® (magnesium L-threonate) for six weeks was associated with improvements in cognitive performance and multiple related outcomes in 100 healthy adults (ages 18–45) with self-reported dissatisfied sleep. 

Reported results included improvements in overall cognitive performance, working and episodic memory, faster reaction time, improved PROMIS sleep-related impairment, a 7.5-year reduction in estimated brain cognitive age, and favorable changes in physiological stress markers (reduced resting heart rate and increased heart rate variability).

These findings were published as “The effect of magnesium L-threonate (Magtein®) on cognitive performance and sleep quality in adults: a randomized, double-blind, placebo-controlled trial” in Frontiers in Nutrition (Front. Nutr., Volume 12 (2025), published January 12, 2026.

The new results also build on—and help reaffirm—earlier clinical evidence in older adults. In the randomized, double-blind, placebo-controlled trial “Efficacy and Safety of MMFS-01, a Synapse Density Enhancer, for Treating Cognitive Impairment in Older Adults: A Randomized, Double-Blind, Placebo-Controlled Trial,” published in the Journal of Alzheimer’s Disease (2016; 49(4): 971–990; published online October 27, 2015), supplementation with a regimen containing magnesium L-threonate (L-TAMS) was associated with significant improvements in overall cognitive ability versus placebo.

Study Highlights

Participants supplementing with Magtein demonstrated:

• Improved overall cognitive performance
• Greater improvements in working and episodic memory
• A 7.5-year reduction in estimated brain cognitive aging
• Faster reaction times
• Reduced resting heart rate (HR) and increased heart rate variability (HRV)
•  Improvement in PROMIS sleep-related impairment

Study Design and Measures

• The six-week study enrolled 100 healthy adults (18–45 years) with self-reported dissatisfied sleep who were randomized to receive 2g/day of Magtein or placebo.
• Cognitive performance was assessed using the NIH Cognitive Toolbox
• Physiological stress markers (including HR and HRV) were collected via Oura
•  Ring wearable sleep-tracking
• Sleep quality was also measured via self-report tools including PROMIS Sleep
• Reaction time and hand–eye coordination were evaluated using a digital aim traine

“This study adds meaningful clinical data to the growing body of evidence on Magtein,” said Dr. Jennifer Gu, senior vice president of R&D at Magtein said. “While earlier studies have demonstrated Magtein supports cognitive performance in older populations, this research suggests benefits may also extend to younger adults—along with additional outcomes related to cognitive function, sleep-related measures, and physiological markers such as heart rate variability, which is shown here for the first time.”