RESEARCH MONOGRAPH · KDC-MN-167

Magnesium L-Threonate

May 9, 2026 Kodiac biolabs Research Revised May 30, 2026 2 min read

Our opinion on this compound

59/100

The CNS-targeted magnesium story is real but oversold, and the gram-cost is brutal

Magnesium L-threonate (sold as Magtein) came out of MIT-based work from Guosong Liu's group, with the original 2010 Neuron paper showing that this specific magnesium form raised CSF magnesium in rodents and improved synaptic density and learning in aged animals. That paper is real, it replicated to some degree in the same lab, and it's the foundation under everything.

The mechanism story is that threonate as a counter-ion enables a particular absorption-and-distribution pattern that gets magnesium across the blood-brain barrier more efficiently than other magnesium salts. CSF magnesium is the relevant pool for NMDA receptor modulation, synaptic plasticity, and the cognitive effects people are after.

Here's where it gets honest. The rodent data is consistent, the human data is thinner. There are a handful of small human trials, mostly Magtein-sponsored, showing modest cognitive improvements in older adults at 1.5-2g daily of the threonate salt. The effect sizes are real but not striking, and independent academic replication outside the original group has been limited.

The dosing reality is brutal. To get a useful elemental magnesium dose from threonate (which is only about 8% magnesium by mass) you need 1.5-2g of the salt daily, which works out to maybe 144mg of elemental magnesium. So you're paying premium prices for a form that delivers less elemental magnesium than a cheap magnesium glycinate or citrate, on the theory that the threonate distribution profile compensates for that. Sometimes it might, sometimes the difference probably gets lost in the noise.

Sourcing-wise Magtein is the branded form and the only one with the supporting studies. Generic magnesium threonate exists but the literature is specifically on Magtein, and reproducing that exact salt purity matters.

What we like: the CSF-targeting concept is mechanistically interesting and the rodent biology is real. What we dont like: the human data hasnt caught up to the marketing, the cost-per-elemental-magnesium is the worst in the category, and most users would probably get better outcomes from cheaper glycinate plus a separate cognition strategy.

Keep it in the library as a research tool, not a default choice.

Evidence: 50
Mechanism: 65
Reliability: 55
Safety: 85
Sourcing: 65
Value: 35
Signal: 60
Staying power: 55

Plain-language summary Intrigue 58 / 100

Magnesium L-threonate is a magnesium salt designed to penetrate the blood-brain barrier better than other magnesium forms. Developed by MIT researchers and marketed as Magtein for cognitive support. Clinical evidence is limited. Not stocked by Kodiac. This monograph is provided for research and educational reference.

Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

Magnesium salt of L-threonate

A proprietary magnesium salt (Magtein) with claimed superior CNS bioavailability for cognitive applications.

Abstract

Magnesium L-Threonate (Magtein; CAS 778571-57-6) is a proprietary magnesium salt developed at MIT by Guosong Liu's group, complexing magnesium with two molecules of L-threonate (a vitamin C metabolite). The complex was designed for CNS delivery; rodent studies showed elevated brain magnesium levels and synaptic density improvements with chronic supplementation, distinguishing it from other magnesium salts which produce less reliable CNS magnesium elevation. Phase 2 trials in mild cognitive impairment have shown modest but consistent improvements in cognitive endpoint measures. Reported research dose ranges in the literature are described in the source publications. The compound is sold as Magtein-branded products and generic equivalents.

Mechanism of action

Magnesium salt with claimed superior CNS bioavailability. Synaptic density improvements in rodent models.

Reported research dose ranges

Reported research dose ranges in the literature.

References

Slutsky I, et al. Enhancement of learning and memory by elevating brain magnesium. Neuron 2010.

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KDC-MN-167

The full reference document is provided strictly for research use only. It reports research dose ranges from the published literature, not instructions for use in humans or animals.

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FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

Kodiac sells research compounds for investigative use only.

Magnesium L-Threonate

Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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