Comparison
Magnesium L-Threonate vs Magnesium Glycinate
Magnesium L-Threonate
MIT-developed magnesium that crosses the blood-brain barrier. Shown to enhance synaptic density and reduce 'brain age'.
Magnesium Glycinate
Chelated magnesium with high bioavailability and minimal laxative effect. The de facto sleep magnesium.
| Field | Magnesium L-Threonate | Magnesium Glycinate |
|---|---|---|
| Category | neuroprotective | neuroprotective |
| Dose range | 1000–2000mg | 200–400mg |
| Half-life | 6h | – |
| Onset | – | – |
| Evidence | EVIDENCEB | EVIDENCEB |
| Safety | ●●●●● | ●●●●● |
| Legal (US) | USOTC | USOTC |
| PubMed refs | 90 | 1200 |
The comparison in plain English
Two magnesium forms with different uses. L-Threonate (Magtein) is the only oral magnesium that meaningfully raises CSF magnesium, it was developed at MIT specifically for brain penetration. Glycinate is highly bioavailable systemic magnesium with the calming bonus of glycine.
Bottom line
L-Threonate is the cognitive choice; Glycinate is the relaxation choice. Many users take both at different times of day. L-Threonate is expensive.
Choose Magnesium L-Threonate if
You want the cognitive 'brain magnesium' effect, synaptic density, sleep depth, the Liu 2016 'brain age' reduction. 1500mg threonate (delivering ~144mg elemental Mg) at night.
Choose Magnesium Glycinate if
You want general magnesium support, anxiety reduction, or sleep onset. 200–400mg glycinate at night.