tuneTypical Dose
1,500–2,000 mg per day
Amino Acid
Magnesium L-Threonate
Magnesium L-threonate (Magtein)
Evidence TierBWADA NOT PROHIBITED
watchEffect Window
6–12 weeks for cognitive effects.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Magnesium L-threonate is a magnesium salt marketed for brain delivery and synaptic support. It is used for cognitive complaints and sleep quality goals, based on early mechanistic evidence.
Animal studies show increased brain magnesium and improved learning and synaptic markers. Small human trials suggest possible cognitive benefits in older adults with subjective impairment and in some adults with poor sleep, but evidence remains early and product-specific. A more clinical oncology trial also found opioid-sparing and constipation benefits, which is interesting but too specialized to generalize into broad pain-relief claims.
Crosses the blood-brain barrier to raise brain magnesium levels, upregulating NMDA receptors and increasing synaptic density in the prefrontal cortex and hippocampus.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Improves executive function and working memory in older adults with cognitive impairment (Liu 2016)
Secondary Outcomes
- Raises brain magnesium levels and synaptic density (animal data)
- Potential sleep quality improvement at evening doses
Safety
Contraindications and Interactions
Contraindications
- Severe kidney disease
Side effects
- Headache
- Drowsiness
- GI upset
Interactions
- Bisphosphonates (separate 2h)
- Tetracyclines (separate 2h)
- Fluoroquinolones (separate 2h)
Avoid if
- Severe renal impairment
- Dialysis
Evidence
Study-level References
magnesium-l-threonate-SRC-001RCT
Sourceopen_in_newLiu G, et al. "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.
Population: Older adults (50–70) with cognitive impairment
Dose protocol: 1,500–2,000 mg MgT daily for 12 weeks
Key findings: Significant improvements in executive function, working memory, and episodic memory. Authors have financial ties to the patent holder.
Paper content
Significant improvements in executive function, working memory, and episodic memory. Authors have financial ties to the patent holder.
magnesium-l-threonate-SRC-002Animal study (rats)
Sourceopen_in_newSlutsky I, et al. "Enhancement of learning and memory by elevating brain magnesium." Neuron. 2010.
Population: Young and aged rats
Dose protocol: MgT supplementation (oral) over multiple weeks
Key findings: MgT increased brain Mg levels, enhanced synaptic density, and improved short- and long-term memory. Foundational study demonstrating BBB penetration of this Mg form.
Paper content
MgT increased brain Mg levels, enhanced synaptic density, and improved short- and long-term memory. Foundational study demonstrating BBB penetration of this Mg form.
magnesium-l-threonate-SRC-003Randomized double-blind placebo-controlled trial
Sourceopen_in_newLopresti AL, Smith SJ. Magtein effects on cognitive performance and sleep quality in adults: randomized placebo-controlled trial. Front Nutr. 2026;12:1729164. PMID:41601871
Population: Adults 18-45 with dissatisfied sleep (n=100)
Dose protocol: Magtein 2 g/day for 6 weeks in adults with dissatisfied sleep.
Key findings: Randomized placebo-controlled trial reported improved cognition and some sleep-related outcomes, but the study remained product-specific and exploratory.
Notes: Useful for modernizing sleep and cognition language without overclaiming class-wide efficacy.
Paper content
Improved cognition and some sleep-related outcomes
magnesium-l-threonate-SRC-004Randomized, double-blind, placebo-controlled trial.
Sourceopen_in_newHausenblas 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. PMID:39252819.
Population: Adults aged 35 to 55 with self-assessed sleep problems.
Dose protocol: 1 g per day MgT versus placebo for 21 days in adults aged 35 to 55 with sleep problems
Key findings: Significant improvements in deep sleep, REM sleep, mood, energy, alertness, and productivity versus placebo.
Notes: Second independent RCT for MgT sleep benefits. Short duration (21 days) and self-report measures are limitations.
Paper content
This 21-day randomized placebo-controlled trial tested 1 g per day of magnesium L-threonate in 80 adults aged 35 to 55 with self-reported sleep problems. The MgT group showed significant improvements in deep sleep scores, REM sleep, and activity measures compared to placebo. Subjective improvements included better mood, energy, alertness, and productivity. The study adds a second independent RCT endpoint for MgT beyond the earlier Liu 2016 cognitive trial, supporting both sleep and daytime functioning benefits. The short duration and self-report measures are limitations.
magnesium-l-threonate-SRC-005Randomized, double-blind, placebo-controlled, longitudinal superiority trial
Sourceopen_in_newWu S, Jin T, Ma B, Ji Y, Huang X, Wang P, Liu X, Krylov BV, Liu X, Ma K. Oral application of magnesium-L-threonate enhances analgesia and reduces the dosage of opioids needed in advanced cancer patients. Cancer Med. 2023;12(4):4343-4351. doi:10.1002/cam4.4922. PMID:36703238.
Population: Adults with advanced cancer and clinically meaningful cancer pain who were using oral opioids.
Dose protocol: 1.5 to 2.0 g/day according to body weight for 90 days in advanced cancer patients using oral opioids.
Key findings: Reduced morphine dose escalation and improved opioid-related constipation versus placebo.
Notes: Strong within its oncology context, but the population is too specialized to justify a broad pain-relief claim.
Paper content
This double-blind randomized oncology trial tested once-daily oral magnesium L-threonate as an adjunct to opioid therapy for 12 weeks in 83 adults with advanced cancer pain. The main signal was opioid sparing rather than lower raw pain scores. Morphine-equivalent dose escalation became significantly lower in the L-TAMS group by day 30 and remained lower through days 60 and 90. Constipation outcomes also favored L-TAMS strongly, with adjusted Wexner scores separating from day 7 onward. By contrast, average VAS pain intensity, breakthrough cancer pain frequency, PHQ-9, and GAD-7 outcomes did not show clear between-group improvement. This makes the study useful as supportive-care evidence for opioid tolerance and opioid-related constipation in a specific cancer population, not as a broad analgesic or mood claim for magnesium L-threonate.