Magnesium L-threonate (Magtein)
Specialty magnesium form developed at MIT for brain-Mg elevation, small RCT signal in cognition; widely popularised but evidence remains preliminary.
Why
Magnesium L-threonate is a magnesium-vitamin C metabolite chelate developed by the Liu/Tonegawa group at MIT specifically to elevate brain magnesium concentrations. Slutsky 2010 Neuron documented improvements in learning and memory in aged rats. Small human RCTs (Liu 2016 J Alzheimers Dis, Hausenblas 2022) report modest cognitive-performance improvements at 1.5–2 g/day. Has been heavily popularised by the Huberman podcast and others; honest framing is preliminary.
How it works
Threonate vehicle improves CNS bioavailability of magnesium across the blood-brain barrier, animal studies show greater CSF and brain-tissue Mg elevation than other oral forms at matched elemental Mg dose. Brain Mg elevation modulates NMDA receptor function and synaptic plasticity.
Expected onset · Cognitive endpoints over 6–12 weeks
How to take
Dosage
1.5–2 g magnesium L-threonate daily (delivering ~144 mg elemental magnesium), often divided 1 g morning + 1 g evening.
Timing
Divided morning and evening with food
On the label
'Magtein' is the trademarked form used in the published trials. Stated mg of magnesium L-threonate (not just elemental Mg) per dose.
Ideal for
Adults with subjective memory complaints or seeking cognition-focused magnesium supplementation, with awareness that evidence is preliminary and the form is far more expensive than other magnesium salts.
Safety
Evidence
Liu 2016 J Alzheimers Dis RCT (n=44 older adults with cognitive impairment): MMFS-01 25 mg/kg/day for 12 weeks improved Trail Making Test and overall cognitive composite scores vs placebo. Preliminary, RCTs exist in non-tier-1 journals but are small or short-duration. No Cochrane review, EMA monograph or EFSA-authorised claim covers the indication. The Huberman-driven popularity has outpaced the published evidence base.
Preliminary, RCTs exist in non-tier-1 journals but are small or short-duration. No Cochrane review, EMA monograph or EFSA-authorised claim covers the indication.
- Slutsky et al., Neuron 2010, enhancement of learning and memory by elevating brain magnesium (preclinical)
- Liu et al., J Alzheimers Dis 2016, efficacy and safety of MMFS-01 (magnesium L-threonate) on cognitive impairment of executive function and memory (RCT)
- Hausenblas et al., Bioactive Compounds in Health and Disease 2022, effect of magnesium L-threonate on cognitive function: pilot RCT
Where to get it
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