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Magnesium salt supplement · Fact sheet

Magnesium L-threonate

Also known as Magtein

Magnesium L-threonate is a magnesium salt studied for cognition and sleep. A short adult trial found improvements on some measures but no between-group improvement in objective sleep outcomes; test-derived cognitive age is not biological age reversal.

Not FDA approvedEarly human evidence
Brain, mood & sleep

What is Magnesium L-threonate?

The mass of magnesium L-threonate includes the salt structure and is not the mass of elemental magnesium.

Different magnesium salts and products containing additional ingredients cannot inherit the same trial findings.

Benefits & claims

Interest in Magnesium L-threonate spans cognition and sleep. Study findings apply to the named formulation and population.

What the evidence supports

  • Some cognitive composite and memory outcomes favored the studied product.
  • Several other cognitive and sleep outcomes were negative.
  • A change in an estimated cognitive-age score does not demonstrate that the brain has become biologically younger.
Research areas
  • Formulation-specific human outcomes
  • Mechanistic research

Dosage & frequency

Human study context

This is an exposure from a named human study, not a generally established treatment or enhancement regimen.

2026 Magtein adult cognition and sleep trial

100 adults aged 18–45 with self-reported dissatisfied sleep

Amount
2 g of the studied magnesium L-threonate product
Frequency
Daily for six weeks
Route studied or labeled
Oral

This is total product/salt mass, not 2 g elemental magnesium. Selected subjective and cognitive effects did not include objective sleep improvement. The source supplies full product and eligibility details.

The effects of magnesium L-threonate (Magtein®) on cognitive performance and sleep quality in adults: a randomised, double-blind, placebo-controlled trial.
How to read these amounts

An approved regimen belongs to a specific product, indication, and population. A study regimen describes what researchers tested; it does not establish a prescription or a safe self-use protocol. Products, routes, and formulations are not interchangeable. A prescriber uses the full label and individual clinical circumstances.

Personal accounts may describe amounts, schedules and outcomes beyond clinical research. They do not establish a regimen. Read the reported experiences

Formulations, interactions & practical context

Formulation differences

  • Different magnesium salts and products containing additional ingredients cannot inherit the same trial findings.

Interactions & precautions

  • The reviewed sources do not establish a comprehensive human interaction profile for this exact substance or combination.

What is still unresolved

  • Reproducibility in larger independent trials
  • Long-term outcomes and adverse effects
  • Equivalence of different preparations and interaction profiles
The effects of magnesium L-threonate (Magtein®) on cognitive performance and sleep quality in adults: a randomised, double-blind, placebo-controlled trial. Oral application of magnesium-L-threonate enhances analgesia and reduces the dosage of opioids needed in advanced cancer patients-A randomized, double-blind, placebo-controlled trial. NIH ODS: magnesium

Side effects & risks

  • Excess magnesium can cause diarrhea and, with impaired renal clearance or excessive exposure, serious toxicity.
  • Magnesium can interfere with absorption of some antibiotics and bisphosphonates; the trial does not establish every interaction.

This is a summary of the cited evidence, not a complete product label. A lack of human safety data does not establish safety.

Clinical research

Early human evidence

A 100-person, six-week trial reported selected cognitive and self-reported sleep effects. Raven test results and ring-measured sleep did not differ significantly between groups.

Studies

Personal experiences

Reports describe what someone noticed. They cannot establish cause, typical results, or how often a side effect happens. Amounts and schedules describe the individual account, not an effective or safe dose. Product identity and strength may be unverified, and missing details are left explicit.

Explore 2 sourced accounts by reported effect.

Sleep: reported experiences

Mixed account · personal report

Calm focus and enjoyable dreams, with a concerning sleep movement

After changing magnesium formulations, an author described calm focus and unusually vivid dreams that they enjoyed. In a reply, the same author also reported accidentally striking their partner during what they described as a hypnic jerk.

Reported use in this account

Product
Magnesium threonate supplement
Amount
4 g of the threonate product, described by the author as providing 288 mg elemental magnesium
Frequency
One nighttime exposure described
Route
Not specified clearly
Duration
One night

Other exposures described: Recently changed from magnesium glycinate

This is an unverified account of a sleep event, not a diagnosis of a sleep disorder. The timing of that movement relative to the product is unclear. A recent formulation change and a single-night observation prevent conclusions about sleep quality or typical effects.

Read the original account
Negative account · personal report

Repeated nightmares after bedtime use

Another author described recurrent bad dreams after magnesium L-threonate before bed, contrasting them with their usual lack of memorable dreams. In replies they acknowledged having misread the elemental-magnesium amount on the label.

Reported use in this account

Product
Magtein magnesium L-threonate capsules
Amount
Not specified clearly
Frequency
Before bed; daily use described in a reply
Route
Not specified clearly
Duration
Not specified clearly

The original milligram claim was corrected in the discussion: 144 mg elemental magnesium referred to three capsules, not each capsule. A precise delivered amount remains unresolved and is not reproduced as a dose.

Read the original account

Approval status

No FDA-approved Magnesium L-threonate drug indication is established for the supplement uses discussed here. Supplement availability is not FDA approval of efficacy or safety.

No FDA-approved product for this entry

Approval covers the labeled product, use and population. A trial phase does not establish success; a stopped program is not ongoing research.

Open questions

  • Reproducibility in larger independent trials
  • Long-term outcomes and adverse effects
  • Equivalence of different preparations and interaction profiles

Summary

A change in an estimated cognitive-age score does not demonstrate that the brain has become biologically younger.

Sources

Medical evidence and regulatory sources are listed here. Personal reports are linked separately in the experiences section.

  3. nihNIH ODS: magnesium

    Magnesium safety, kidney-related toxicity risk and interactions with selected medicines.

How we assess sources · Suggest a correction