Magnesium L-Threonate vs Glycinate: Research and Cost
Buy magnesium glycinate. It gives more magnesium per capsule and costs about half as much per mg: $1.10 against $2.15 for 300 mg at list price. L-threonate is the form studied for memory, but its human trials are small and were all run or paid for by the companies behind it.
The verdict
For everyday magnesium, sleep, or simply topping up what food misses, buy glycinate. Our pick, Nature Made, gives 200 mg of magnesium in 2 capsules and is on USP Verified. Choose L-threonate only if your goal is memory or focus and you accept thin, company-funded evidence. A full serving gives 144 mg of magnesium; Double Wood’s is the lowest cost of the three we price.
Informational comparison of two magnesium forms, not medical advice. If you notice memory changes, see a doctor rather than treating them yourself. Prices are each brand’s list price, checked October 14, 2026.
L-Threonate vs Glycinate, Side by Side
| Glycinate | L-threonate (Magtein) | |
|---|---|---|
| What it is | Magnesium bound to glycine, an amino acid | Magnesium bound to L-threonic acid; sold as Magtein |
| Share that is magnesium | About 14% | About 7.2% |
| Magnesium a serving | 200 mg in 2 capsules (Nature Made) | 144 mg in 4 capsules (Double Wood); 3 capsules for other brands |
| Studied for | Sleep (one 2025 trial); general magnesium intake | Memory and thinking; sleep (small trials) |
| Who ran the trials | A university group; one author runs a research firm paid by supplement companies (sleep trial) | The developer, supplier or owner of Magtein, in all 3 |
| Testing list | USP Verified (Nature Made) | None of the 3 we price |
| 300 mg of magnesium | $1.10 | $2.15 (lowest of 3) |
| Buy | Check price | Check price |
Does L-Threonate Reach the Brain Better?
In rats, yes. In people, it has not been measured the same way. The idea comes from a 2010 MIT study: rats given L-threonate had more magnesium in their brain fluid, more connections between brain cells, and did better on learning and memory tasks (Slutsky 2010). That is why it is marketed for the brain.
Glycinate has no brain-specific claim. It raises magnesium in the body like other well-absorbed forms. NIH’s fact sheet names neither form when it lists the forms that absorb best; small studies favored citrate, aspartate, lactate and chloride over oxide (NIH). So “better absorbed” is not a fair claim for either one.
Every Human Trial of L-Threonate We Found
Three placebo-controlled trials. In each one, a company that developed, supplies or owns Magtein paid for the trial or employed some of its authors (last column), and none has been repeated by an independent group.
| Trial | Who and dose | What it found | Who paid or ran it |
|---|---|---|---|
| Liu 2016 | 44 adults 50 to 70 with memory or thinking complaints; 1.5 to 2 g a day of an L-threonate product (MMFS-01), by body weight, 12 weeks | A combined thinking score improved more than on placebo. Sleep and anxiety could not be judged: the placebo group improved too much. | Neurocentria, the developer; three authors worked there |
| Hausenblas 2024 | 80 adults 35 to 55 with sleep complaints; 1 g a day (about 72 mg of magnesium), 3 weeks | Better deep and REM sleep scores on a sleep ring, and better morning mood and energy, than placebo. | Three authors work for AIDP, Magtein’s supplier |
| Lopresti 2026 | 100 adults 18 to 45 unhappy with their sleep; 2 g a day (144 mg of magnesium), 6 weeks | A combined thinking score and reaction time improved more than on placebo; a reasoning test did not. Sleep: one self-rated score improved; the sleep ring showed no difference. | Threotech, which owns Magtein |
Glycinate’s record is different, not longer. Its best trial is for sleep: 155 adults who slept poorly took 250 mg of magnesium as bisglycinate or a placebo for 4 weeks, and insomnia scores fell a little more on magnesium (Schuster 2025). No trial has tested glycinate for memory, and no trial has put the two forms head to head.
Cost: L-Threonate Pays for Little Magnesium
Only 7.2% of magnesium L-threonate is magnesium, so a 2,000 mg serving gives 144 mg. Every L-threonate we price uses the same Magtein ingredient at that dose; only the capsule count and the price differ. That makes it a costly way to get magnesium:
At each brand’s list price, 300 mg of magnesium as L-threonate costs $2.15 to $3.47 across the 3 we price; Double Wood is the lowest. Our glycinate pick costs $1.10.
One serving of L-threonate covers 144 mg, about a third to a half of the 310 to 420 mg adults need from food and supplements together. If you are low on magnesium, glycinate fills the gap for less. All 3 L-threonates, priced by serving and by bottle size.
Taking Both: How Much of Each
You can take both if you count the magnesium. One L-threonate serving (144 mg) plus 2 capsules of our glycinate pick (200 mg) is 344 mg, just under the 350 mg daily limit for magnesium from supplements (food does not count). If a multivitamin or a calcium-magnesium pill adds more, cut the glycinate to 1 capsule.
Who Each One Is For
- Most people, for everyday magnesium or sleep: glycinate. Nature Made Magnesium Glycinate, 200 mg in 2 capsules, USP Verified, $0.73 a day at list price.
- You want to dose glycinate by the tablet: Vitamin Shoppe Magnesium Glycinate 400 mg. 135 tablets, 133 mg each. Take 1 or 2: the 3-tablet serving (400 mg) is over the limit. Not on a testing list.
- Your goal is memory or focus, and you accept company-funded evidence: L-threonate. Double Wood Magnesium L-Threonate is the lowest cost of the three we price. The trials ran 3 to 12 weeks, so give it at least that long.
- You have kidney disease: ask your doctor before either. Weak kidneys cannot clear the extra, so it can build up (NIH).
Antibiotics: take tetracyclines (such as doxycycline) or quinolones (such as ciprofloxacin) at least 2 hours before or 4 to 6 hours after magnesium (NIH).
Frequently Asked Questions
Is magnesium L-threonate better than glycinate?
For most people, no. Glycinate gives more magnesium per capsule and costs about half as much per mg at list price. L-threonate is the form studied for memory, but its 3 human trials are small and were run or paid for by the companies behind Magtein. Pick L-threonate only if memory is your goal and you accept that.
Is magnesium L-threonate better for the brain?
In rats, yes: L-threonate raised brain magnesium and improved learning and memory (Slutsky 2010). In people, two industry-funded trials found gains on thinking tests over 6 to 12 weeks (in the 2016 trial, a large effect on an overall score in 44 people). No independent group has repeated them, and no trial has compared L-threonate with glycinate.
Which is better for sleep, L-threonate or glycinate?
Neither is proven better. Glycinate has the largest recent placebo trial (155 adults, a small benefit; Schuster 2025). L-threonate has two smaller trials tied to its maker with mixed results. All the magnesium sleep trials.
Can I take magnesium L-threonate and glycinate together?
Yes, if you count the total. One full L-threonate serving (2,000 mg of Magtein) gives 144 mg of magnesium. Two capsules of our glycinate pick give 200 mg. Together that is 344 mg, just under the 350 mg daily limit for supplements (NIH). Add nothing else with magnesium, such as a multivitamin, without counting it.
How much magnesium is in magnesium L-threonate?
About 7.2% of the compound is magnesium. A 2,000 mg serving of Magtein (3 or 4 capsules, by brand) gives 144 mg of magnesium. Glycinate is about 14% magnesium, so the same weight carries about twice as much. Read the “Magnesium” line on the label: that is the amount you get.
Why is magnesium L-threonate so expensive?
Magtein is a trademarked ingredient sold by one supplier, and each capsule holds little magnesium, so you need more of them. At list price, 300 mg of magnesium as L-threonate costs $2.15 to $3.47, against $1.10 for our glycinate pick. What each L-threonate costs.
Does L-threonate cause side effects?
The trials reported it as well tolerated. In the longest one, most side effects were mild, and fewer were reported on L-threonate than on placebo (Liu 2016). A serving holds 144 mg of magnesium, a modest amount; no trial has compared its stomach effects with glycinate. If you have kidney disease, ask your doctor before any magnesium (NIH).
Related
- Magnesium L-threonate prices · magnesium for sleep · all 8 forms compared
- Glycinate vs citrate · oxide vs glycinate · best magnesium glycinate
- Best magnesium overall · how much magnesium per day · magnesium guide
Sources
- Slutsky I, et al. Enhancement of learning and memory by elevating brain magnesium. Neuron. 2010 (rats). PubMed 20152124
- Liu G, et al. Efficacy and safety of MMFS-01, a synapse density enhancer, for treating cognitive impairment in older adults. J Alzheimers Dis. 2016. PubMed 26519439 (funded by Neurocentria)
- Hausenblas HA, et al. Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems. Sleep Med X. 2024. PubMed 39252819
- Lopresti AL, Smith SJ. The effects of magnesium L-threonate (Magtein) on cognitive performance and sleep quality in adults. Front Nutr. 2026. PubMed 41601871 (funded by Threotech)
- Schuster J, et al. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep. Nat Sci Sleep. 2025. PubMed 40918053
- NIH Office of Dietary Supplements. Magnesium fact sheet for health professionals (updated January 6, 2026; read October 14, 2026).
- Labels: Nature Made (NIH label 322551, 200 mg per 2 capsules); Double Wood (NIH label 315679, 2,000 mg Magtein giving 144 mg of magnesium per 4 capsules). Prices: each brand’s own list price, checked October 14, 2026. We quote no Amazon prices.