In short: Magnesium L-threonate, often simply called magnesium threonate, is magnesium bound to L-threonic acid. There are dedicated studies on this form and the brain. In controlled human studies, adults taking threonate performed better on memory tests and had better deep-sleep readings. Typical amounts are 1 to 2 g a day. Because it contains just over 8% magnesium, you combine it with a second form to cover your daily needs.
Key points
- Studied for the brain: threonate has its own studies on memory and sleep. In rats, it raised magnesium levels in the brain.
- Memory: in three controlled studies, adults taking threonate scored better on memory and thinking tests than with placebo.
- Sleep: in a study of 80 adults, deep-sleep and REM-sleep readings improved, and participants felt fresher in the morning.
- In practice: 1 to 2 g of threonate provide about 75 to 165 mg of magnesium. For your daily needs, pair it with a second magnesium form.
- In the EU: authorised as a novel food since November 2024, for adults, not for pregnant or breastfeeding women.
Contents
- What is magnesium L-threonate?
- How much magnesium does it contain?
- Does threonate really reach the brain?
- Who developed it, and is it allowed in the EU?
- What does magnesium do in the brain?
- Benefits: what do studies in humans show?
- Threonate compared with other forms
- Why is magnesium L-threonate so expensive?
- How much and when should you take it?
- Side effects: is threonate dangerous?
- Conclusion
- Frequently asked questions
- Limits of the research and all sources
What is magnesium L-threonate?
Magnesium L-threonate is a salt made of one magnesium and two molecules of L-threonic acid. This acid is a small sugar-derived compound. It's considered a breakdown product of vitamin C. It also occurs naturally in the fluid that surrounds the brain and spinal cord.6
In shops you'll find several spellings: magnesium L-threonate, magnesium threonate, magnesium l threonate, or simply MgT. They all refer to the same compound. The best-known branded raw material is called Magtein.
What the studies show: the chemical database PubChem lists the compound with the molecular formula C8H14MgO10 and a molar mass of 294.50 g/mol.1 The EU Food Safety Authority (EFSA) has confirmed that the body can absorb the magnesium from it.2
How much magnesium is in magnesium L-threonate?
Pure magnesium L-threonate is just over 8% magnesium. The rest is threonic acid — precisely the carrier that this form is all about. For shopping, that means: the pack often shows a large number, but it usually refers to the threonate, not the magnesium.
Here's how the figure comes about: magnesium weighs 24.3 units, the whole compound 294.5. Divide one by the other and you get 8.25% (our calculation from the PubChem figures).1 Commercial raw materials contain some water and come in a little lower. In two studies using the branded raw material, it was 72.5 and around 75 mg of magnesium per gram.10, 11
In practice: Look on the pack for the figure "of which magnesium" per daily serving. That's the number that counts for your intake.
- 2,000 mg of magnesium L-threonate provide about 145 to 165 mg of magnesium.
- 1,000 mg of magnesium L-threonate provide about 73 to 83 mg of magnesium.
- For 250 mg of magnesium you need around 3,000 mg of threonate. With 500 mg capsules, that's six of them.
(Our calculation from the molar mass and the figures in the studies.)
The EU authorisation reflects this: the maximum of 3,000 mg of threonate a day corresponds, according to EFSA, to exactly 250 mg of magnesium — the upper limit for magnesium from food supplements.2, 18
Does magnesium L-threonate really reach the brain?
In animal studies, yes. That's exactly where its reputation as "magnesium for the brain" comes from. In humans, brain magnesium levels haven't been measured directly so far.
Some background: between blood and brain sits the blood-brain barrier. It's a tight layer of cells around the brain's fine blood vessels. It lets nutrients and oxygen through and keeps many other substances out. How much magnesium reaches the brain is regulated by the body itself.
What the studies show: in the original 2010 study, threonate raised magnesium levels in the brains of rats. Afterwards, the animals performed better in learning and memory tests.5 In nerve cells in the lab, threonate increased the magnesium content inside the cell; other magnesium salts didn't.6
Our take: the animal studies provide a plausible explanation for why threonate is interesting for the brain. They were the starting point for the studies in humans. Those didn't measure brain magnesium levels, but what matters in everyday life: memory and sleep. You'll find those results further down.
Who developed magnesium L-threonate, and is it allowed in the EU?
The compound comes from a research group led by neuroscientist Guosong Liu at the Massachusetts Institute of Technology (MIT). The first major publication appeared in 2010.5 Liu later studied the form in humans too, including in the 2016 memory study.8
In the EU, magnesium L-threonate was long not authorised. As a "novel food" it needed its own approval. That's where the search "is magnesium L-threonate banned" comes from. That has now changed:
| Step | Date | What it means |
|---|---|---|
| EFSA safety opinion | January 2024 | safe up to 3,000 mg of threonate a day for adults; magnesium is absorbed |
| Authorisation as a novel food | 7 November 2024 | permitted in food supplements, not for pregnant or breastfeeding women |
| Addition to the list of magnesium sources | November 2025 | threonate is officially an approved magnesium compound |
Sources: EFSA opinion and EU regulations.2, 3, 4
One special point: because of data protection for the submitted study data, only the applicant AIDP is allowed to place the substance on the EU market until 7 November 2029.3
What does magnesium do in the brain?
Magnesium is needed for nerves and the psyche, and that's officially confirmed. Three authorised health claims apply. They hold for every form of magnesium, including threonate:
- Magnesium contributes to normal functioning of the nervous system.
- Magnesium contributes to normal psychological function.
- Magnesium contributes to a reduction of tiredness and fatigue.
What the studies show: in observational studies, people with both too-low and too-high blood magnesium had memory problems more often. A large review found a U-shaped curve for this, with the most favourable level around 0.85 mmol/l.15 So the goal is good supply, not as much as possible.
Benefits: what do studies in humans show?
In humans, mainly memory and sleep have been studied. In both areas, controlled studies found better results than with placebo. Here's an overview of the individual areas:
Memory and concentration
This is where threonate is best studied. Three controlled studies found better test results than with placebo, in both older and younger adults. Participants took 1.5 to 2 g of threonate a day, for 30 days to twelve weeks.
What the studies show: in a study of 44 adults aged 50 to 70, all with mild memory problems, overall performance on thinking tests improved more after twelve weeks than with placebo.8 In a Chinese study of 109 adults, the threonate group scored better on a memory test after 30 days. The product also contained phosphatidylserine and vitamins C and D.9 In an Australian study of 100 younger adults, the overall score on a test battery improved after six weeks, especially for working and episodic memory.10
Sleep
There are positive results for sleep too. The study that looked specifically at sleep found better readings for deep and REM sleep, and participants felt fresher in the morning.
What the studies show: 80 adults with sleep problems took 1 g of threonate or a placebo for three weeks. A sleep-tracking ring showed better readings for deep and REM sleep in the threonate group; participants felt fresher in the morning and reported better mood and more energy.11 In the Australian study, the everyday consequences of poor sleep also improved.10
You can read more about magnesium and sleep, including other forms, in our article on magnesium glycinate.
Dementia and ADHD: what has been studied?
Both have been looked at in small early studies. They show the direction research is heading. As a food supplement, threonate isn't intended to treat any disease.
What the studies show: 15 people with mild to moderate Alzheimer's dementia took threonate for eight weeks. A short test of mental performance turned out somewhat better afterwards.13 In a pilot study of 15 adults with ADHD, symptoms improved in just under half.14 Further Alzheimer's findings come from experiments in mice that develop Alzheimer's-like changes. Among other things, threonate changed the gut flora in these mice and repaired the gut barrier.16, 17
Does threonate protect brain cells?
There are early indications from animal studies. In mice that develop Alzheimer's-like changes, threonate was linked to fewer lost nerve connections and better-preserved memory performance.16 Whether this carries over to humans is something future studies need to show.
Our take: threonate is the magnesium form most specifically researched for the brain. The animal studies are thorough, and the human studies point in the same direction: better results on memory tests and for deep sleep. That makes threonate interesting for adults who particularly care about everyday concentration or restful sleep. The studies used 1 to 2 g a day, usually split between morning and evening, over several weeks. For your daily magnesium needs, it's best combined with a form that contains more magnesium per gram. How strong the effects really are is something larger and longer studies still need to show.
Magnesium L-threonate compared with other forms
Threonate was developed specifically for the brain and studied in brain research. In exchange, it has the lowest magnesium content of the common forms. Put together, that gives a simple rule of thumb: threonate at the studied amount of 1 to 2 g, plus a form with a higher magnesium content, such as citrate or bisglycinate, for your daily needs.
| Form | Magnesium content (pure) | Powder for 250 mg magnesium | Studies specifically on the brain |
|---|---|---|---|
| Magnesium oxide | 60.3% | approx. 0.4 g | none |
| Magnesium citrate (trimagnesium dicitrate) | 16.2% | approx. 1.5 g | none |
| Magnesium bisglycinate | 14.1% | approx. 1.8 g | none, sleep study available |
| Magnesium L-threonate | 8.3% | approx. 3.0 g | animal studies + human studies on memory and sleep |
Shares: our calculation from the molar masses in PubChem, without crystal water.1 How well the body absorbs the different forms is compared in our article Which magnesium is best?
Why is magnesium L-threonate so expensive?
Mainly for two reasons: for the same amount of magnesium, you need more powder, and in the EU the raw material currently comes from only one supplier.
- Quantity effect: for the same amount of magnesium, you need around 1.7 times as much threonate as bisglycinate. Compared with magnesium oxide, it's just over 7 times as much (our calculation from the table above). More powder means more or larger capsules.
- One supplier: until November 2029, only AIDP is allowed to place the raw material on the EU market.3 That means there's no competition among raw-material makers for now.
- Research and brand: threonate is backed by animal and human studies since 2010, and a branded raw material. These costs feed into the price.
How much magnesium L-threonate should you take, and when?
In the studies, adults mostly took 1 to 2 g of threonate a day, which is about 75 to 165 mg of magnesium. The EU authorisation doesn't provide for more than 3 g of threonate a day.2, 3
Tip: Always calculate with the magnesium, not the threonate. For your daily needs, you can combine threonate well with a second form that provides more magnesium per gram, such as citrate or bisglycinate. Both then count together: from all food supplements combined, aim for no more than 250 mg of magnesium a day.18 How much you need in total is covered in How much magnesium per day?
When? In the studies, the amount was usually split: one portion in the morning, one in the evening, or the whole amount two hours before bed.10, 11 Regularity matters more than the exact time. More on this in When should you take magnesium?
How long? The studies ran for three to twelve weeks, and results were measured after that time. So plan for at least a few weeks of regular use.
Side effects: is magnesium L-threonate dangerous?
No, at the authorised amounts it's considered safe. EFSA has assessed threonate as safe for adults up to 3,000 mg a day.2 In the studies, it was well tolerated.
Possible side effects are the same as for any magnesium: loose stools, diarrhoea, or a feeling of pressure in the stomach, mainly with larger amounts taken at once. At the usual 1 to 2 g of threonate, you only get about 75 to 165 mg of magnesium — below the upper limit of 250 mg.
What the studies show: in the twelve-week study with older adults, 20% of the threonate group had gastrointestinal complaints, compared with 15% in the placebo group. The difference wasn't significant.8 The raw material may contain up to 1% oxalic acid. EFSA considers the resulting amount of up to 30 mg a day safe.2
Important: Pregnant and breastfeeding women should not take magnesium L-threonate; the EU authorisation explicitly excludes them.3 With reduced kidney function, magnesium can build up in the body; talk to your doctor first in that case.19 With thyroid hormone, certain antibiotics and osteoporosis medicines, you need a gap of a few hours — details in When should you take magnesium? New or worsening memory problems belong in a doctor's hands.
What happens with too much magnesium is explained in our article Too much magnesium.
Conclusion
Magnesium L-threonate is the magnesium form most specifically researched for the brain. In animal studies, it raised magnesium levels in the brain. In studies with humans, participants scored better on memory tests and had better readings for deep sleep. Magnesium contributes to normal functioning of the nervous system.
Here's how to use it: 1 to 2 g of threonate a day, ideally split between morning and evening, over several weeks. Because threonate contains just over 8% magnesium, combine it with a form with a higher magnesium content for your daily needs. Overall, stay at no more than 250 mg of magnesium from food supplements.
Frequently asked questions
What does magnesium L-threonate do? It provides magnesium, and magnesium contributes to normal functioning of the nervous system. In controlled studies, adults taking threonate also scored better on memory tests and had better readings for sleep quality.8, 10, 11
Which magnesium is best for the brain? Threonate was developed specifically for the brain and has its own studies on it.5 The officially authorised health claims on nerves and the psyche apply to every magnesium form. If you take threonate, you can add a form with more magnesium per gram for your daily needs.
Does magnesium L-threonate help you sleep? 80 adults with sleep problems took 1 g of threonate a day for three weeks. Afterwards, they had better readings for deep and REM sleep and felt fresher in the morning.11 In another study, the everyday consequences of poor sleep also improved.10
Is magnesium L-threonate banned in the EU? No, not anymore. Since 7 November 2024, it has been authorised in the EU as a novel food for food supplements. Before that, it couldn't legally be sold as a food in the EU.3
What do user experiences say? Experience reports are individual opinions. Studies with a placebo group are more informative, because they factor out the placebo effect. How large that can be was shown in the study with older adults: for sleep and mood, the placebo group improved noticeably too.8
Capsules or powder? For the effect, it makes no difference. With powder, you see the amount directly: for 250 mg of magnesium, that's about 3 g. Capsules are more convenient, but you need several a day.
Limits of the research and all sources
Almost everything known about threonate and the brain comes from experiments in rats, mice and cell cultures.5, 6, 16, 17 Whether threonate gets more magnesium into the human brain than other forms has never been measured directly. A more recent rat study found that magnesium acetyltaurate got more magnesium into the brain than threonate did.7 Direct comparisons with other magnesium forms in humans are missing altogether.
In humans, there are five controlled studies with around 440 participants combined, none longer than twelve weeks. Funding matters for threonate: all four studies with a positive result were paid for by companies that develop or sell threonate (Neurocentria, Wuxi Magtein Bioscience, ThreoTech, AIDP).8, 9, 10, 11 The only study without any apparent manufacturer link found no difference in sleep, mood and thinking performance in 109 women after breast cancer surgery. It did, however, look at a very different group.12 Independent confirmation is therefore still missing.
Even in the positive studies, not every measure improved. The Chinese study used a combination product.9 In the Australian study, there was no difference for logical reasoning, for disturbed sleep itself, or for the sleep-ring readings.10 In the sleep study with 80 participants, part of the difference came from the placebo group getting worse.11 In the older adults, sleep and anxiety couldn't be assessed because of a strong placebo effect.8 The Alzheimer's and ADHD studies had 15 participants each and no placebo group. In Alzheimer's, only one test out of several improved, and the researchers themselves warn against overinterpretation.13, 14 For magnesium in general, a review of twelve controlled studies rates the evidence for sleep as weak and inconsistent.20 Whether extra magnesium improves memory couldn't be settled by the few controlled studies in the large review on dementia.15
Show all 20 sources
| # | Study | Who was studied | Result | Strength of evidence |
|---|---|---|---|---|
| 1 | PubChem CID 45489777 (plus CID 84645, 6099959, 14792) | Chemical database | Molar mass threonate 294.50 g/mol → 8.25% magnesium; bisglycinate 14.1%, citrate 16.2%, oxide 60.3% | Reference data, our calculation |
| 2 | EFSA NDA Panel 2024, EFSA Journal | Regulatory opinion | safe up to 3,000 mg/day (= 250 mg magnesium), magnesium is absorbed, ≤1% oxalic acid considered safe | official assessment |
| 3 | Commission Implementing Regulation (EU) 2024/2694 | European Commission | authorisation from 7 Nov 2024, not for pregnant/breastfeeding women, data protection for AIDP until 7 Nov 2029 | legal act |
| 4 | Commission Delegated Regulation (EU) 2025/2225 | European Commission | threonate added to the list of approved magnesium sources | legal act |
| 5 | Slutsky et al. 2010, Neuron | Rats (MIT) | more magnesium in the brain, better learning and memory performance | animal study |
| 6 | Sun et al. 2016, Neuropharmacology | Nerve cell cultures | threonate raises magnesium in the cell, other salts don't; threonate present in cerebrospinal fluid | cell study |
| 7 | Kumar et al. 2026, Neuromolecular Med | Rats | magnesium acetyltaurate got more magnesium into the brain than threonate | animal study, contrary finding |
| 8 | Liu et al. 2016, J Alzheimers Dis | 44 adults (50–70y) with memory problems, 1.5–2 g/day, 12 weeks | better overall performance on thinking tests; sleep/anxiety not assessable due to placebo effect | controlled study, funded by Neurocentria (developer) |
| 9 | Zhang et al. 2022, Nutrients | 109 adults (18–65y), 2 g combination product with phosphatidylserine, vit. C and D, 30 days | better result on memory test | controlled study, funded by Wuxi Magtein Bioscience; combination product |
| 10 | Lopresti & Smith 2026, Front Nutr | 100 adults (18–45y) with unsatisfactory sleep, 2 g (145 mg Mg), 6 weeks | better overall thinking-test score and reaction time; no difference for logical reasoning, sleep disturbance and sleep-ring readings | controlled study, funded by ThreoTech |
| 11 | Hausenblas et al. 2024, Sleep Med X | 80 adults (35–55y) with sleep problems, 1 g (approx. 75 mg Mg), 21 days | better sleep-ring readings for deep and REM sleep, mood, energy | controlled study, funded by AIDP, 3 authors employed by AIDP |
| 12 | Ni et al. 2023, Breast Cancer (Dove) | 109 women after breast cancer surgery, 12 weeks | no difference in pain, sleep, mood, thinking performance | controlled study, no apparent manufacturer link; contrary finding |
| 13 | Wroolie et al. 2017, Pers Med Psychiatry | 15 people with Alzheimer's dementia, 8 weeks | short mental performance test (MMSE) somewhat better, other tests not | open-label study without placebo |
| 14 | Surman et al. 2020, J Diet Suppl | 15 adults with ADHD, up to 12 weeks | just under half with fewer symptoms | open-label pilot study without placebo, funded by Neurocentria |
| 15 | Chen et al. 2024, Adv Nutr | 3 controlled + 12 observational studies | U-shaped curve for blood magnesium and dementia risk; too few controlled studies for a conclusion | systematic review |
| 16 | Li et al. 2014, Mol Brain | Alzheimer's model mice | less loss of nerve connections and memory performance | animal study |
| 17 | Liao et al. 2023, Neural Regen Res | Alzheimer's model mice | changed gut flora, repaired gut barrier | animal study |
| 18 | EFSA / SCF 2001 | Regulatory opinion | upper limit 250 mg magnesium/day from food supplements | official assessment |
| 19 | Rosner et al. 2023, Mayo Clin Proc | Review | build-up with reduced kidney function | review |
| 20 | Lopresti et al. 2026, J Diet Suppl | 12 controlled studies on magnesium and sleep | inconsistent results, weak to very weak evidence | systematic review |
Author: PRONESIUM Editorial Team · Last reviewed: 29/09/2026 · This article does not replace medical advice.
