**Magtein** is a patented form of **Magnesium L-Threonate** — the only magnesium form shown in human trials to cross the blood-brain barrier and raise brain magnesium levels. At 2g per serving (3 capsules), you're getting the exact dose used in the clinical research on memory, learning, and cognitive function. That yields 144mg of elemental magnesium, which sits comfortably within the supplemental range for general magnesium benefits like muscle relaxation, sleep support, and stress management.

The brain-health angle is what sets this apart. If your goal is cognitive support — sharper recall, better focus, or age-related memory concerns — this delivers the studied dose in full. Magnesium deficiency is extremely common and often undetected, so even the baseline magnesium support here is meaningful for energy, mood, and nerve function.

The tradeoff is pill burden and total magnesium. Three capsules daily gives you just 144mg of elemental magnesium — well under the 310–420mg RDA for total intake. If you're looking for broader magnesium coverage for muscle cramps or heart health, you'd need to supplement additional magnesium in another form alongside this.

BioStacks
Source Naturals

Magtein Magnesium L-Threonate 667 mg

3 Capsules · 30 servings

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What it does

Magnesium

Mixed formsGrade —

Supports normal muscle and nerve function and helps the body produce energy.

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Ingredients (2)

Nutrition

Calories, macros & sodium.

  • Calories10 Calorie(s)

Other ingredients

MaltodextrinBinder

Spikes blood sugar faster than table sugar (glycemic index 85–105). Research links it to gut bacteria changes that may promote intestinal inflammation (Nickerson et al. 2015). Used as a cheap filler — adds nothing beneficial.

Magnesium StearateLubricant

A salt of stearic acid used as a lubricant in tablet and capsule production

Silicon DioxideAnti-caking

Fine silica powder used to prevent clumping

GelatinCapsule

Protein derived from collagen, used in traditional capsule shells

Lab testing

How to take it

With or without food
Space it a couple of hours from Iron and Calcium

On the label

Suggested Use: 3 capsules daily, preferably in divided doses. Start with 1 capsule daily and gradually increase to 3 capsule's daily.

Price check

$30.79

$10$20$50

Pricier than 78% of 579 magnesium supplements

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Sources & Scoring

Nutrient data (RDA, UL, and safety thresholds) sourced from the NIH Office of Dietary Supplements and the National Academies Dietary Reference Intakes (DRI).

This is not medical advice. Consult a healthcare provider before making changes to your supplement routine.

The score analyzes what's on the label: ingredient doses vs. studied ranges, chemical forms, evidence levels, and known interactions. It does not verify label accuracy or test for contaminants — for that, look for third-party certifications like USP or NSF.

Not medical advice. Consult your healthcare professional.

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