Magnesium L-Threonate: The Only Form of Magnesium That Reaches the Brain
Introduction
Magnesium is one of the most essential minerals in the human body — a cofactor in over
300 enzymatic reactions, critical for energy production, cardiovascular health,
neuromuscular signalling, and nervous system function. Yet despite its importance, research
consistently shows that approximately 50% of the population in industrialised countries
consumes less than the recommended daily intake of magnesium, and roughly 30% of the
global population shows inadequate dietary magnesium status.
Most people know magnesium for its role in muscle relaxation and sleep. What fewer people
know is that the brain has its own, highly specific magnesium requirements — and that most
common forms of magnesium supplement fail to cross the blood-brain barrier in meaningful
quantities.
One form, however, was specifically engineered to solve this problem: Magnesium L-
Threonate.
The Blood-Brain Barrier Problem
The brain is protected by the blood-brain barrier (BBB) — a highly selective cellular
membrane that controls which substances can pass from the bloodstream into neural tissue.
Most magnesium supplements (magnesium citrate, glycinate, oxide, chloride, sulfate) are
absorbed in the gut reasonably well, but their ability to significantly elevate magnesium
levels in the central nervous system and cerebrospinal fluid is very limited.
This is a critical limitation because the brains cognitive functions — memory, learning, focus,
and synaptic plasticity — are directly dependent on adequate magnesium levels in neural
tissue, particularly in the hippocampus, the brain region responsible for memory
consolidation.
The MIT Discovery: Magnesium L-Threonate
In 2010, a research team from the Massachusetts Institute of Technology (MIT), led by Dr.
Inna Slutsky and Professor Guosong Liu, published a landmark study in the journal Neuron
that changed the understanding of magnesium and brain health. The team developed a
novel compound — magnesium bound to L-threonate (a natural metabolite of Vitamin C) —
called Magnesium L-Threonate (MgT).
The results were remarkable. In their animal studies, MgT was the only form of magnesium
tested that could significantly elevate cerebrospinal fluid magnesium concentrations —
increasing levels by 7% to 15% within 24 days of oral supplementation, while other common
magnesium forms showed no meaningful increase in brain magnesium.
The MgT-treated subjects demonstrated:
▸ Enhancement of both short-term working memory and long-term spatial memory
▸ Improved pattern completion abilities, especially in aged subjects
▸ Increased density of synaptic connections (synaptogenesis) in the hippocampal DG and
CA1 regions
▸ Upregulation of NR2B-containing NMDA receptors, which are critical for synaptic
plasticity and learning
▸ Elevated levels of Brain-Derived Neurotrophic Factor (BDNF) — the brains own growth
hormone
Human Clinical Evidence
The preclinical promise of Magnesium L-Threonate has been confirmed in multiple human
trials:
A randomised, double-blind, placebo-controlled trial published in Nutrients (2022) involving
109 healthy adults aged 18–65 demonstrated that a Magnesium L-Threonate-based formula
significantly improved scores on the Clinical Memory Test after just 30 days of
supplementation (2g/day), compared to placebo.
A 2025 randomised, double-blind, placebo-controlled trial published in Frontiers in Nutrition,
involving 100 adults aged 18–45, supplemented with 2g daily of Magnesium L-Threonate for
6 weeks. The study showed statistically significant improvements in cognitive performance
scores and sleep quality compared to placebo. Magtein also received FDA Generally
Recognized As Safe (GRAS) approval in 2012, and in November 2024, earned Novel Food
status in the European Union.
Why Magnesium L-Threonate Is Different
Superior Brain Bioavailability
Unlike other forms, MgT uses glucose transporters to cross the blood-brain barrier, achieving
significant elevation of cerebrospinal fluid magnesium — a feat no other common magnesium
form has replicated.
Synaptic Density Enhancement
MgT uniquely increases the number of functional synaptic connections in the hippocampus,
strengthening the structural basis of memory and learning.
BDNF Elevation
MgT supplementation raises hippocampal BDNF — the protein responsible for neuron
growth, survival, and plasticity. Higher BDNF is consistently associated with better cognitive
performance and protection against age-related decline.
Clean Tolerability
Unlike high-dose standard magnesium, which can cause gastrointestinal upset, MgT's high
absorption at lower doses minimises the risk of digestive side effects.
Who May Benefit Most
✓ Students and professionals with demanding cognitive workloads
✓ Adults aged 40+ experiencing age-related memory changes
✓ Individuals with high stress levels (stress accelerates magnesium depletion)
✓ People with sleep disturbances (poor sleep and low brain magnesium are bidirectionally
linked)
✓ Athletes seeking cognitive as well as physical recovery
References
[1] Slutsky I, Abumaria N, Wu LJ, et al. Enhancement of Learning and Memory by Elevating Brain
Magnesium. Neuron. 2010;65(2):165-177. doi:10.1016/j.neuron.2009.12.026. PubMed PMID:
20152124.
[2] Zhang C, Hu Q, Li 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. PMC9786204.
[3] 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. Frontiers in
Nutrition. 2025;12:1729164. doi:10.3389/fnut.2025.1729164.
[4] 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;108:426-439. doi:10.1016/j.neuropharm.2016.05.006. PubMed PMID: 27181058.
Sacred Leaves · Research Articles · sacredleaves.global
Sacred Leaves Private Limited · GMP Certified · www.sacredleaves.global | Page 4
[5] Uysal N, Kizildag S, Yuce Z, et al. Timeline (bioavailability) of magnesium compounds in hours: which
magnesium compound works best? Biol Trace Elem Res. 2019;187(1):128-136.
doi:10.1007/s12011-018-1351-9.
[6] de Baaij JHF, Hoenderop JGJ, Bindels RJM. Magnesium in man: implications for health and disease.
Physiol Rev. 2015;95(1):1-46. doi:10.1152/physrev.00012.2014. PubMed PMID: 25540137.