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Magnesium Glycinate vs L-Threonate for the Brain
Magnesium glycinate vs l-threonate is a choice between two ways of packaging the same mineral. Glycinate pairs magnesium with the amino acid glycine. L-threonate pairs it with a vitamin C breakdown product. Synaptril lists glycinate only. No form has a proven effect on thinking in healthy adults.
Written by the Synaptril label deskUpdated · 4 min read
The short answer01
What is the difference between magnesium glycinate and L-threonate?
Magnesium glycinate and L-threonate are two magnesium salts. The mineral is the same. The partner molecule is different.
Glycinate is magnesium bound to glycine, an amino acid. L-threonate is magnesium bound to threonic acid. Marketing for the second form often talks about the brain.
The Synaptril label lists magnesium glycinate only: 80 mg of magnesium per capsule, in a gentle form. L-threonate is not on the bottle. Read the full panel in the Supplement Facts breakdown.
Side by side02
How do the two forms compare?
On paper, the forms differ in partner molecule, marketing and what is printed on labels. They do not differ in a proven brain result.
| Point | Glycinate | L-threonate |
|---|---|---|
| Partner molecule | Glycine | Threonic acid |
| Magnesium by weight | About 14% for pure glycinate (Magnesium glycinate, Mg content) | Not in our sources |
| On the Synaptril label | Yes, 80 mg magnesium | No |
| Proven to help thinking | No | No |
Magnesium content is a chemistry estimate for pure glycinate, not a measured value for any product.
The research03
Does any magnesium form help memory or focus?
No magnesium form has been shown to sharpen thinking in healthy adults. A 2024 review found too few randomized trials of magnesium supplements to draw conclusions (Chen 2024, Magnesium and cognition).
Blood magnesium showed a U-shaped link with dementia risk. Risk was lowest near 0.85 mmol/L and higher both below and above that mark (Chen 2024, Magnesium and cognition). That is an association, not proof that a pill changes it.
Our reference list holds no trial that compares glycinate with L-threonate head to head. So any claim that one beats the other is not something this desk can check.
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See packsChoosing04
How should you choose between the two?
Start with the label, not the form name. Check the milligrams of elemental magnesium, the other ingredients and your own medicines.
- Find "magnesium" in the Supplement Facts and note the mg.
- Stay under 350 mg a day from supplements unless a doctor says otherwise (NIH ODS, Magnesium).
- Ask a pharmacist about antibiotics and bisphosphonates, which need a gap from magnesium (NIH ODS, Magnesium).
- Compare cost per day, not per bottle.
Never stop or change a prescription because of a supplement. Ask your doctor or pharmacist first.
On the bottle05
Where does Synaptril fit?
Synaptril uses magnesium glycinate and nothing else from the L-threonate family. The 80 mg is about 19% of the Daily Value.
It sits first in a 575 mg blend, so it likely takes most of the weight. See the magnesium glycinate page for the math, or all seven label lines.
FAQ06
Glycinate and L-threonate questions
Is magnesium L-threonate in Synaptril?
No. The Synaptril label lists magnesium as magnesium glycinate from a proprietary blend, 80 mg of magnesium per capsule. L-threonate does not appear anywhere on the Supplement Facts panel or in the other ingredients list printed on the bottle.
Is magnesium glycinate gentler on the stomach than other forms?
Our sources do not rank glycinate for stomach comfort. NIH says high supplemental magnesium commonly causes diarrhea, nausea and cramping whatever the form (NIH ODS, Magnesium). Dose matters most, so stay near the label amount and talk to a pharmacist.
Does L-threonate cost more than glycinate?
This desk has no verified price comparison for the two forms, so it states none. Compare any two products by cost per day of elemental magnesium, and check the milligrams on each Supplement Facts panel before you decide.
Can you take two magnesium forms together?
Only after adding up the elemental magnesium from every product. NIH sets 350 mg a day from supplements as the upper level for adults (NIH ODS, Magnesium). Two products can pass that line quickly, so ask a doctor or pharmacist first.
Which form do human trials favor for cognition?
None. A 2024 meta-analysis found too few randomized trials of magnesium supplements to draw conclusions on cognitive health (Chen 2024, Magnesium and cognition). Studies of specific forms are fewer still, so treat any winner declared by a brand with caution.
Do I need either form if I eat enough magnesium?
Maybe not. NIH lists adult needs of 310 to 420 mg a day, and foods supply magnesium (NIH ODS, Magnesium). A supplement fills a gap only if you have one. A doctor can help decide that, and no pill replaces your prescribed medicine.
Who wrote this07
Written and reviewed by
Pages built from the label, the sales page and linked NIH, FDA, CDC, FTC and peer-reviewed sources.
Last updated . See our editorial standards and how we check reviews. This website is run by Getsynaptril, a stocked U.S. Synaptril counter, not by the manufacturer or the distributor. We are paid when you buy through our order links.
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