Magnesium L-Threonate (branded as Magtein®) is a patented magnesium molecule that delivers 144mg of elemental magnesium per 2-capsule serving at roughly $0.50 to $1.00 per dose across the three dominant brands: Life Extension Neuro-Mag, Nutricost Magtein, and Double Wood Magtein. It carries less elemental magnesium per serving than glycinate or citrate and costs more per gram. The label pitch is a specific magnesium compound, not a general-purpose magnesium supplement. We audited the supplement facts panels, the cost-per-gram math, and the ingredient counts across all three Magtein products to map where this form earns its shelf space and where it does not.
What Is Magnesium L-Threonate? The Label Breakdown
Magnesium L-Threonate is a patented magnesium compound sold under the brand name Magtein®, where magnesium is bound to L-threonic acid, a metabolite of vitamin C. The standard serving across all Magtein® products is 2 capsules delivering 2,000mg of magnesium L-threonate, which provides 144mg of elemental magnesium on the supplement facts panel. This is the label spec. Two capsules. Two thousand milligrams of the compound. One hundred forty-four milligrams of elemental magnesium. Every Magtein® bottle prints this.
The elemental magnesium content of 144mg per serving is the number to compare against other magnesium forms. Magnesium glycinate typically delivers 200-400mg of elemental magnesium per serving. Magnesium citrate lands between 200-300mg. Magnesium oxide can hit 400-500mg. Magtein® sits at the bottom of that range on elemental content and at the top on cost per gram. This is the trade-off printed on every label. For broader nootropic context, see our Onnit Alpha Brain review and the Genius Mushrooms vs Alpha Brain comparison.
The ingredient panel on a standard Magtein® product lists Magnesium (as Magnesium L-Threonate) from Magtein®, a vegetable cellulose capsule, and typically one flow agent like rice flour or magnesium stearate. Three to four ingredients total. No proprietary blends. No filler magnesium forms hiding behind the Magtein® label. This is a short-panel supplement by category standards.
The Sports Car vs. The Pickup Truck Analogy
Magnesium glycinate is a pickup truck. It hauls a big load of elemental magnesium (200-400mg) to your whole body. Magnesium L-Threonate is a sports car. It carries a smaller payload (144mg) to a specific destination. The pickup does not win a drag race. The sports car does not haul lumber. Stop asking which vehicle is better. Ask which one fits the job you are actually doing.
Magnesium L-Threonate vs Other Magnesium Forms: Label Specs
Magnesium L-Threonate (Magtein®), magnesium glycinate, magnesium citrate, and magnesium oxide are four different compounds printed on four different supplement labels, each with a different elemental magnesium count, ingredient panel, and cost per gram. The form printed on the label determines how much elemental magnesium you get per capsule and what you pay for it.
| Form | Typical Serving | Elemental Mg/Serving | Common Use | Cost Per Serving |
|---|---|---|---|---|
| L-Threonate (Magtein®) | 2 capsules (2,000mg) | 144mg | Memory, focus, sleep quality | $0.50-$1.00 |
| Glycinate | 2-4 capsules | 200-400mg | Relaxation, muscle tension | $0.15-$0.35 |
| Citrate | 2-3 capsules | 200-300mg | Digestion, bowel regularity | $0.10-$0.25 |
| Oxide | 1-2 capsules | 400-500mg | Low-cost label filler | $0.03-$0.08 |
Magtein® is the most expensive magnesium form per gram of elemental magnesium, and it delivers the lowest elemental magnesium per serving of the four common forms. That is the spec sheet, not a value judgment. It is the wrong magnesium for someone who wants maximum elemental magnesium per dollar. It is the right magnesium for someone who wants the specific compound on the label and is willing to pay the premium. For more on supplement label transparency, see our non-caffeine supplements guide.
Best Magnesium L-Threonate Supplements: Three Magtein Products Ranked
All three products use the same Magtein® (Magnesium L-Threonate) compound at the 2,000mg delivering 144mg elemental magnesium standard dose. The difference between them is brand, capsule count, price per bottle, and third-party testing documentation.
Life Extension Neuro-Mag: The Legacy Brand Pick
Life Extension Neuro-Mag lists Magnesium (as Magnesium L-Threonate) from Magtein®, vegetable cellulose capsule, rice flour, and vegetable stearate on the label. Four ingredients. The standard 144mg elemental magnesium per 2-capsule serving. Life Extension is a legacy longevity brand with in-house third-party testing documentation and a longer track record than Nutricost or Double Wood. The bottle count is typically 90 capsules, a 45-day supply at the standard dose. Price runs higher than Nutricost, reflecting the brand premium and testing overhead.
| Serving | 2 capsules = 2,000mg Magtein, 144mg elemental Mg |
| Bottle | 90 capsules (45 servings) |
| Ingredients | Magnesium L-Threonate, vegetable cellulose, rice flour, vegetable stearate |
| Testing | In-house third-party verified |
Nutricost Magtein: The Value Pick
Nutricost Magtein lists the same Magnesium (as Magnesium L-Threonate) from Magtein® on its supplement facts panel, with a gelatin capsule, rice flour, and magnesium stearate rounding out the label. Also four ingredients. Also 144mg elemental magnesium per 2-capsule serving. Nutricost consistently prices below Life Extension, making this the cost-per-serving winner of the three. The bottle count varies by SKU; the 180-capsule option is the best value, providing a 90-day supply at the standard dose. Nutricost uses third-party testing but provides less brand-level documentation than Life Extension. For more Nutricost product breakdowns, see our Nutricost K2 D3 review and Nutricost multivitamin review.
| Serving | 2 capsules = 2,000mg Magtein, 144mg elemental Mg |
| Bottle | 180 capsules (90 servings) for the value SKU |
| Ingredients | Magnesium L-Threonate, gelatin capsule, rice flour, magnesium stearate |
| Testing | Third-party tested |
Double Wood Magtein: The Minimalist Pick
Double Wood Magtein prints Magnesium (as Magnesium L-Threonate) from Magtein® on a label with a vegetable cellulose capsule and minimal excipients. The ingredient panel is the shortest of the three. Standard 144mg elemental magnesium per 2-capsule serving. Double Wood positions itself as the biohacker-friendly brand with clean labels and published certificates of analysis per batch. The bottle is typically 120 capsules, a 60-day supply. Price sits between Life Extension (higher) and Nutricost (lower). For more Double Wood product breakdowns, see our Double Wood Lion’s Mane review and Double Wood Cissus review.
| Serving | 2 capsules = 2,000mg Magtein, 144mg elemental Mg |
| Bottle | 120 capsules (60 servings) |
| Ingredients | Magnesium L-Threonate, vegetable cellulose capsule, minimal excipients |
| Testing | Published certificates of analysis per batch |
Magnesium L-Threonate Pros and Cons
The trade-off is a patented magnesium compound with a short ingredient panel and 144mg elemental magnesium per serving against a premium cost per gram that runs 3x to 10x higher than glycinate or citrate.
Pros
- Patented Magtein® compound: A specific magnesium molecule, not a commodity form
- Short ingredient panels: Three to four ingredients across all three brands
- No proprietary blends: The label tells you exactly how much Magtein® is in each capsule
- Standard dose across brands: 144mg elemental Mg from 2,000mg Magtein®, making brand comparison apples-to-apples
- Available from three established brands: Life Extension, Nutricost, Double Wood — all with third-party testing
Cons
- Low elemental magnesium: 144mg per serving vs 200-400mg in glycinate
- Premium price: $0.50 to $1.00 per serving vs $0.10 to $0.35 for glycinate
- Two capsules per serving: Same pill count as glycinate for less magnesium
- Not a general-purpose magnesium: The lower elemental content makes it inefficient for total magnesium coverage
- Brand premium varies: Life Extension costs more than Nutricost for the same Magtein® compound
Who Magnesium L-Threonate Is For (And Who Should Skip It)
Magtein® is a specific magnesium compound for a specific buyer. It is not a one-size-fits-all magnesium supplement.
Good Fit
- People who want the specific Magtein® compound on their label
- Buyers who care about short ingredient panels (3-4 ingredients)
- Anyone willing to pay a premium for a patented magnesium form
- People stacking magnesium with a nootropic routine who want label transparency
Not the Best Fit
- People who want maximum elemental magnesium per dollar (buy glycinate)
- People using magnesium primarily for digestion (buy citrate)
- Budget buyers under $15 per bottle (oxide and citrate live here)
- Anyone who wants a single-capsule magnesium supplement
- People comparing magnesium by elemental content alone (Magtein® loses this comparison on specs)
The Toolbox Analogy
You do not buy a single wrench and expect it to fix every bolt in the house. Magnesium glycinate is your 10mm wrench. It handles most jobs. Magnesium citrate is your pipe wrench. It does one thing well. Magnesium oxide is the cheap adjustable wrench from the bargain bin. It says “wrench” on the package. Magtein® is the specialized torque wrench. It costs more. It handles fewer bolts. For the bolt it was built for, nothing else in the toolbox fits. Buy the wrench that matches the bolt you are actually tightening.
Magnesium L-Threonate FAQ
- How much elemental magnesium is in Magtein® per serving?
- 144mg of elemental magnesium from 2,000mg of magnesium L-threonate (Magtein®) in 2 capsules. This is the standard dose printed on every Magtein® supplement facts panel across Life Extension, Nutricost, and Double Wood. It is lower than the 200-400mg typical of magnesium glycinate per serving.
- Why does Magtein® cost more than other magnesium forms?
- Magtein® is a patented compound (magnesium L-threonate) that carries a licensing cost not present on commodity magnesium forms like oxide, citrate, or glycinate. The raw material costs more to manufacture. That cost passes through to the bottle price. You are paying for the specific compound on the label, not just the elemental magnesium count.
- Can I take Magtein® with other magnesium forms?
- Yes. Many people run Magtein® alongside magnesium glycinate. The labels list different compounds. There is no ingredient overlap between a Magtein® capsule and a glycinate capsule. As always, consult a qualified professional before stacking supplements, especially if you take medication or have a health condition.
- Which Magtein® brand has the best value?
- Nutricost Magtein in the 180-capsule bottle provides the lowest cost per serving of the three. Double Wood sits in the middle on price with the shortest ingredient panel. Life Extension Neuro-Mag costs the most but carries the longest brand track record and in-house third-party testing documentation.
- How many capsules do I take per day?
- The standard Magtein® serving is 2 capsules per day, delivering 2,000mg of magnesium L-threonate and 144mg of elemental magnesium. Some products recommend taking 1 capsule in the morning and 1 in the evening. Follow the label on the bottle you purchase, not a generic recommendation.
- Is Magtein® the same as regular magnesium?
- No. Magtein® is a specific, patented magnesium L-threonate compound manufactured by AIDP, Inc. Not every magnesium L-threonate product is Magtein®. The Magtein® trademark on the label confirms it is the licensed compound. Generic magnesium L-threonate without the Magtein® trademark is a different raw material.
Final Verdict
Magnesium L-Threonate (Magtein®) is a specific, patented magnesium compound with 144mg of elemental magnesium per 2-capsule serving at a premium price point compared to glycinate, citrate, and oxide. It is not the right magnesium for someone chasing maximum elemental magnesium per dollar. Glycinate wins that column decisively. It is the right magnesium for someone who wants the specific Magtein® compound on their label, values a short ingredient panel, and is willing to pay a premium for a patented form.
The three Magtein® products on the shelf are label-identical on the active compound. Life Extension Neuro-Mag, Nutricost Magtein, and Double Wood Magtein all deliver 144mg of elemental magnesium from 2,000mg of Magtein®. The difference is brand, bottle count, price, and third-party testing documentation. Nutricost wins on cost per serving. Double Wood wins on ingredient-panel minimalism. Life Extension wins on brand track record and testing transparency.
Magnesium supplementation is not one-size-fits-all. The form printed on the label determines the elemental magnesium count, the serving size, and the cost. Magtein® is a specific tool for a specific buyer. Check the supplement facts panel. Compare the elemental magnesium number to what you actually want from a magnesium supplement. Pick the form that matches. That is the entire decision.
Verdict: Magtein Is a Specific Tool, Not a General Magnesium
144mg elemental magnesium per serving. Patented Magtein® compound. $0.50-$1.00 per dose. Buy Nutricost for value, Double Wood for label minimalism, Life Extension for brand track record. Follow the label and consult a professional.
Related Magnesium and Nootropic Guides
- Onnit Alpha Brain Review
- Genius Mushrooms vs Alpha Brain
- Genius Mushrooms Review
- Real Mushrooms Lion’s Mane Review
- Double Wood Lion’s Mane Review
- Non-Caffeine Supplements Guide
- Nutricost K2 D3 Review
- Nutricost Multivitamin Review
- Life Extension NAD+ Review
- Mushroom Supplement Spec Guide
- Nutricost Vitamin K2 D3
