Guide
Magnesium glycinate vs L-threonate
L-threonate's brain-magnesium story starts with a 2010 rat study; its human trials, all funded by the ingredient's patent holder, report more positive results than glycinate's own literature. Here's the full comparison.
Magnesium L-threonate (sold under the patented name Magtein) is marketed on its ability to raise magnesium levels in brain tissue, a finding from 2010 animal research; magnesium glycinate makes no such claim. L-threonate carries less elemental magnesium per gram than glycinate, and its human trials, while more numerous than glycinate's, are all funded by the ingredient's patent holder.
The two forms, side by side
| Magnesium glycinate | Magnesium L-threonate | |
|---|---|---|
| Formula | C4H8MgN2O4 | C8H14MgO10 |
| Molar mass | 172.42 g/mol (PubChem CID 84645) | 294.50 g/mol (PubChem CID 45489777) |
| Elemental magnesium by weight | ~11–14% | ~8% |
| Typically sold for | General daily supplementation, sleep marketing | Brain/cognitive marketing, sold under the patented name Magtein |
| Origin of the marketing story | Animal and older-adult trials in sleep, at higher doses in different forms | A single 2010 rat study showing increased brain magnesium and improved learning tasks |
| Human trial funding | Mixed; some independent, one industry-funded | All three located trials funded by the patent holder (Threotech / AIDP) |
| Watch out for | Sleep and absorption claims outrun the evidence | Typical daily dose (1–2 g) is 4–8× a glycinate serving by compound weight, and every human trial is industry-funded |
Where the L-threonate story comes from
A 2010 study in rats found that a newly developed compound, magnesium-L-threonate, raised magnesium levels in the brain and improved learning ability, working memory, and short- and long-term memory, with older rats also showing improved pattern-completion. That's the animal finding the entire L-threonate marketing category is built on. It's a real result — in rats, at a dose scaled for rats, on a mechanism that hasn't been directly confirmed in human brain tissue.
What the human trials found
Three human randomized trials exist, and all three were funded by the companies that hold the Magtein patent (Threotech and AIDP). A 2022 trial gave 109 healthy Chinese adults 2 g/day of a combined formula — L-threonate plus phosphatidylserine and vitamins C and D, not L-threonate alone — for 30 days, and found improved scores on a standard memory test; because it tested a multi-ingredient formula, the result can't be attributed to L-threonate specifically. A 2024 trial gave 80 adults with self-reported poor sleep 1 g/day of L-threonate alone for 21 days and reported improvements on several subjective and wearable-device sleep measures. A 2025 trial gave 100 adults 2 g/day for six weeks and found a statistically significant improvement on one cognitive composite score (p=0.043) and one subjective sleep-impairment measure (p=0.043), alongside several null secondary measures and no group difference on the objective wearable-device sleep data.
Read together, this is a more active human literature than glycinate has for sleep or absorption — but every trial in it comes from the party that profits from the ingredient being believed effective, and none has been independently replicated. That's a real difference worth knowing, not a reason to dismiss the results outright.
Elemental magnesium and dose
L-threonate is the least concentrated common form by weight, at roughly 8% elemental magnesium — lower than glycinate's 11–14%. The trials above used 1–2 grams of compound a day, which is 4 to 8 times the compound weight of our own 3-capsule glycinate serving, though that reflects the low elemental percentage as much as a deliberately larger magnesium dose. At 8% elemental, 2 g of L-threonate delivers roughly 160 mg of actual magnesium — below our own 275 mg serving.
Side effects and cost
The two 2024–2025 trials above that reported on tolerability described L-threonate as safe and well tolerated, with no significant adverse reactions versus placebo. The bigger practical difference is price: because L-threonate is a patented, less concentrated compound sold in gram-level daily doses, it's generally the most expensive common magnesium form per gram of elemental magnesium, well above glycinate, citrate or oxide.
Questions people ask
What is the difference between magnesium glycinate and magnesium L-threonate?
Glycinate binds magnesium to glycine and carries more elemental magnesium per gram. L-threonate binds it to threonic acid, carries less elemental magnesium per gram, and is marketed specifically on a 2010 animal finding about brain magnesium levels that glycinate doesn't claim.
Which is better, magnesium glycinate or magnesium L-threonate?
They're marketed for different things. L-threonate's human trials, though all industry-funded, report more positive results than glycinate's do for their respective marketed uses. Neither has been tested head-to-head against the other in a human trial.
Can you take magnesium glycinate and magnesium L-threonate together?
There's no known reason not to combine them, though doing so means adding their elemental magnesium totals against the 350 mg/day supplemental upper limit for most adults, and L-threonate's typical 1–2 g/day dose already contributes a meaningful share of that on its own.
Does magnesium L-threonate actually cross into the brain better than other forms?
That's the claim behind the ingredient, based on the 2010 rat study. It hasn't been directly measured in human brain tissue in the trials we found; the human data instead measures cognitive test scores and sleep questionnaires as indirect outcomes.
Related reading
Sources
- Enhancement of learning and memory by elevating brain magnesium A 2010 study found that magnesium-L-threonate raised brain magnesium levels and improved learning and memory in rats — the animal finding the L-threonate category is marketed on.
- A Magtein(®), Magnesium L-Threonate, -Based Formula Improves Brain Cognitive Functions in Healthy Chinese Adults A 2022 industry-funded trial found a multi-ingredient formula containing magnesium L-threonate improved memory test scores in healthy adults over 30 days — but the formula also contained phosphatidylserine and vitamins, so the effect can't be pinned on the magnesium compound alone.
- Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: A randomized controlled trial A 2024 industry-funded trial found adults with sleep problems who took 1 g/day of magnesium L-threonate for three weeks reported and measured (via a wearable ring) better sleep and daytime function than a placebo group, whose scores declined over the same period.
- The effects of magnesium L-threonate (Magtein(®)) on cognitive performance and sleep quality in adults: a randomised, double-blind, placebo-controlled trial A 2026 industry-funded trial found adults taking 2 g/day of magnesium L-threonate for six weeks improved on one overall cognitive score and one subjective sleep-impairment measure, but most other sleep and wellbeing measures — including every objective sleep-tracker measure — showed no difference from placebo.
- Perspective: Call for Re-evaluation of the Tolerable Upper Intake Level for Magnesium Supplementation in Adults In 7 of 10 trials between 128 and 1,200 mg a day, magnesium caused no more diarrhea than the comparison.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
