The Benefits of Magnesium L-Threonate

Magnesium L‑threonate is a relatively new form of magnesium in which magnesium is bound to L‑threonic acid, a water‑soluble metabolite of vitamin C. Current research suggests that magnesium threonate increases brain magnesium more effectively than other forms as it can cross the blood-brain barrier. Early evidence has shown that supplementation leads to improvements in many aspects of cognitive function, including learning, memory, mood, and sleep quality. This appears to be due to improvements in neural plasticity and reductions in oxidative stress.¹

Note: Studies investigating magnesium supplementation and cognitive performance are currently limited due to magnesium’s low blood-brain permeability. This typically results in minimal increases in brain concentrations of magnesium despite elevated blood concentrations, and therefore reduced cognitive-related benefits.²

A 2026 study in 100 adults found that taking 1g magnesium threonate twice daily for 6 weeks improved overall cognitive skills including executive function, episodic memory, attention, processing speed, and language. Participants showed the most improvement on the List Sorting Working Memory (LSWM) test which involves working memory and episodic memory, suggesting enhanced synaptic plasticity. Brain cognitive age was reduced by an estimated 7.5 years.³

A 2022 study involving 109 healthy Chinese adults taking 2g magnesium threonate a day for a month resulted in significant improvements in directed memory, paired-association learning, free recall of pictures, recognition of figures, and portrait-features memory.  Interestingly, older participants showed more improvement than younger participants.⁴

A 2024 study in 80 adults with sleep issues found that taking 1 g/day magnesium threonate for 21 days resulted in significant improvements in deep and REM sleep scores and light sleep time. Participants also reported improvements in energy, mood, and alertness. Researchers noted that synapse configuration associated with learning and new memory formation occurs during deep sleep, which may explain why magnesium threonate is associated with improved cognitive function.⁵

In the 2026 study mentioned previously, participants also reported significant reductions in perceived stress and anxiety scores, along with less fear‑related symptoms. These findings suggest potential anxiolytic and stress‑modulating benefits.⁶

Current research suggests that magnesium threonate is safe and well-tolerated in most individuals. The EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) concluded that magnesium threonate is a safe, bioavailable magnesium source for adult supplements at up to 3000 mg/day (around 250 mg elemental magnesium), with no need for further toxicity testing.⁷

It should be noted that excess dosages of magnesium can cause diarrhea, stomach cramping, and abdominal pain. Pregnant or breastfeeding women should discuss magnesium supplementation with their doctor first.

Magnesium L‑threonate appears to cross into the central nervous system and increase neuronal magnesium concentrations more effectively than other forms of magnesium. Studies in both animals and humans have shown improved memory, focus, and mental clarity. These effects appear to be due to increases in brain levels of magnesium, which lead to increased synaptic plasticity.⁸

Magnesium in general decreases excessive glutamatergic activity (an excitatory pathway) in the brain, and supports gamma‑aminobutyric acid (GABA), a key inhibitory neurotransmitter. Together, this can reduce neuronal hyperexcitability and support relaxation and sleep quality. Magnesium L‑threonate’s ability to increase brain levels of magnesium may have important benefits for improving mood, anxiety, stress, and sleep quality.⁹

Magnesium threonate supports synaptic density (the number of synaptic connections between neurons) and plasticity (the ability of these connections to change over time). This mechanism is key to learning and memory.¹⁰

Magnesium threonate’s role in maintaining the health and function of neurons, protecting against oxidative stress, and supporting synaptic plasticity may help to reduce the effects of aging.

Magnesium L-threonate supplements are not as readily available as other forms, but capsules and powder can be purchased online and over the counter. 

Capsules provide a concentrated dosage of magnesium threonate that must be swallowed whole. The contents are released when the capsule is broken down in the stomach or intestine.

Powders are often preferred to capsules as this allows more flexibility with dosing. Magnesium is often better tolerated and may be more efficiently absorbed when taken in divided doses rather than a single large dose, and powders can be easily measured and added to foods and beverages. Studies to date have used doses of 1-2g magnesium threonate per day, which is much easier to measure in powder than in multiple capsules.

As with any new supplement, it’s important to follow the manufacturer’s dosage instructions on the product label. If you are new to taking magnesium, it’s best to start with the lowest recommended dose and build up over a few weeks. If you have any specific concerns, talk to your healthcare professional.

Studies suggest that magnesium is best taken in divided doses throughout the day, as your body can only absorb a certain amount of magnesium at once.¹¹ You can do this by taking half of the daily dose in the morning and evening.

Magnesium glycinate and magnesium L‑threonate are both well‑absorbed forms of magnesium, but are typically associated with different benefits. 

Magnesium glycinate is chelated with glycine (an amino acid), which acts as a major inhibitory neurotransmitter in the central nervous system. This form is highly bioavailable and often used for systemic magnesium repletion, muscle function, and relaxation, with a lower risk of gastrointestinal issues than inorganic forms such as magnesium oxide.¹²

You can take magnesium glycinate and L‑threonate together as long as the total amount of elemental magnesium does not exceed the recommended dosage, as excess amounts (rather than different forms) can cause gastrointestinal issues.

L‑threonate and L‑theanine are completely different molecules. L-threonate is a carrier for magnesium that can cross the blood-brain barrier. L-theanine is an amino acid structurally similar to glutamate that can bind to glutamate receptors, reducing neuronal excitotoxicity in the brain and supporting feelings of calm.