Best Magnesium L-Threonate Supplements 2026: Cost per Effective Dose
The lowest-cost magnesium L-threonate is Double Wood Magnesium L-Threonate, $1.03 a day at its list price. All 3 we track use the same Magtein ingredient and give the same 144 mg of magnesium a serving, so price is the main difference: $1.03 to $1.67 a day. For everyday magnesium, glycinate costs about half as much per mg at list price.
Lowest cost for magnesium L-threonate
Double Wood Magnesium L-Threonate
2,000 mg of Magtein (144 mg of magnesium) in 4 capsules, $1.03 a day at Double Wood’s list price for one 120-capsule bottle. Same ingredient and dose as the others, for less. It is not on a testing list for this 4-capsule serving.
Check price on Amazon- Want fewer capsules? Life Extension Neuro-Mag Magnesium L-Threonate gives the same 144 mg in 3 capsules, $1.05 a day at list price.
- Want magnesium for sleep or everyday use, not memory? Nature Made Magnesium Glycinate 200mg, our overall pick: 200 mg in 2 capsules, USP Verified, $0.73 a day. Why it is our pick.
All magnesium L-threonate supplements compared
The 3 we track, ranked by what one 144 mg serving costs at each brand’s own list price, cheapest first. Amazon’s price can differ.
| Product and size | A serving | Per 300 mg | A year |
|---|---|---|---|
| 1 Double Wood Magnesium L-Threonate 120-capsule bottle, list $30.95, 144 mg magnesium in 4 capsules (30 servings)No testing list found · score 5.5/10 | $1.03 | $2.15 | $377 |
| 2 Life Extension Neuro-Mag Magnesium L-Threonate 90-capsule bottle, list $31.50, 144 mg magnesium in 3 capsules (30 servings)No testing list found · score 5.5/10 | $1.05 | $2.19 | $383 |
| 3 NOW Magtein Magnesium L-Threonate 90-capsule bottle, list $49.99, 144 mg magnesium in 3 capsules (30 servings)No testing list found · score 4.5/10 | $1.67 | $3.47 | $608 |
The score (out of 10) weighs testing, dose, cost, label and recalls, and compares L-threonates with each other only. None gives a full dose of magnesium in one serving (144 mg), which lowers each one’s dose mark. How we score.
| Item | Value |
|---|---|
| Double Wood Magnesium L-Threonate | $2.15 |
| Life Extension Neuro-Mag Magnesium L-Threonate | $2.19 |
| NOW Magtein Magnesium L-Threonate | $3.47 |
| Nature Made Magnesium Glycinate 200mg | $1.10 |
Is one L-threonate better than another?
Not on what is inside. All three list “Magtein,” the trademarked magnesium L-threonate, at 2,000 mg a serving, giving 144 mg of magnesium. Each brand buys the same trademarked ingredient. What differs:
- Capsules a serving: 4 for Double Wood, 3 for Life Extension and NOW. Same dose, so each Double Wood capsule holds less.
- Price: $1.03 to $1.67 a serving at list price, a gap of $232 a year at one serving a day.
- Other ingredients: check the label if you avoid gelatin or fillers; Life Extension’s and NOW’s capsules are vegetarian.
How much magnesium you actually get
Only about 7.2% of magnesium L-threonate is magnesium. The 144 mg in a serving is about a third of the 420 mg a day men need and under half of the 320 mg women need, from food and supplements together (NIH). The “Magnesium” line on the Supplement Facts panel is the magnesium itself (the elemental amount), not the weight of the whole compound (NIH).
The human trials used 1 to 2 g of magnesium L-threonate a day, so the 2,000 mg label serving is the top of that range; do not double it. If you also take another magnesium, count both. The upper limit for adults is 350 mg a day of magnesium from supplements and medicines. Food does not count toward it (NIH). Taking L-threonate and glycinate together.
Is any magnesium L-threonate third-party tested?
Not one we could confirm. We searched NSF/ANSI 173, NSF Certified for Sport, USP Verified, Informed Choice and Informed Sport on October 14, 2026. NSF/ANSI 173 lists a Double Wood Magnesium L-Threonate with an 8-capsule serving. The bottle we price and link gives its dose in 4 capsules, so it may be a different version, and we do not count it as listed. We found no listing for Life Extension Neuro-Mag or NOW Magtein. That does not mean their labels are wrong; it means no outside program confirms them. If testing matters most to you, these magnesium glycinates are on a list.
Every size, ranked by cost
All 7 bottle sizes the brands sell
| Product | Size | List price | A serving |
|---|---|---|---|
| Double Wood Magnesium L-Threonate | Triple Pack (3 x 120 capsules) | $82.95 | $0.92 |
| Double Wood Magnesium L-Threonate | Double Pack (2 x 120 capsules) | $56.95 | $0.95 |
| Double Wood Magnesium L-Threonate | One Bottle (120 capsules) (linked) | $30.95 | $1.03 |
| Life Extension Neuro-Mag Magnesium L-Threonate | 90 vegetarian capsules (linked) | $31.50 | $1.05 |
| NOW Magtein Magnesium L-Threonate | 100 Veg Capsules (In Stores Only) | $49.99 | $1.51 |
| NOW Magtein Magnesium L-Threonate | 180 Veg Capsules | $91.65 | $1.53 |
| NOW Magtein Magnesium L-Threonate | 90 Veg Capsules (linked) | $49.99 | $1.67 |
How these 3 magnesium L-threonate products were ranked
By cost a serving at each brand’s own list price: the price of the bottle our link opens, divided by its servings. Every serving is the same 144 mg, so this is also the cost per mg of magnesium. We quote no Amazon prices. Commission does not enter it; the rate is the same whichever you buy.
Questions
What is the best magnesium L-threonate supplement?
On cost, Double Wood Magnesium L-Threonate: 144 mg of magnesium (2,000 mg of Magtein) in 4 capsules, $1.03 a day at its list price. All 3 we track use the same Magtein ingredient at the same dose, so the real differences are price and capsule count. None is on a public testing list for the serving we price.
Which magnesium L-threonate is the cheapest?
Double Wood Magnesium L-Threonate at $1.03 a serving, then Life Extension Neuro-Mag Magnesium L-Threonate at $1.05 and NOW Magtein Magnesium L-Threonate at $1.67, each at the brand’s one-bottle list price. Double Wood’s 2- and 3-bottle packs cost less per serving.
How many capsules give the 144 mg of magnesium on the label?
About 7.2% of the compound. A 2,000 mg serving of Magtein gives 144 mg of magnesium; that is the “Magnesium” line on each of these labels. It takes 3 capsules (Life Extension, NOW) or 4 (Double Wood).
How much magnesium L-threonate should I take?
The trials used 1 to 2 g of magnesium L-threonate a day (about 72 to 144 mg of magnesium). The label serving, 2,000 mg, is the top of that range. Keep all magnesium from supplements at or under 350 mg a day (NIH).
Is magnesium L-threonate third-party tested?
Not the products we price. We searched five public testing lists on October 14, 2026. NSF/ANSI 173 lists a Double Wood Magnesium L-Threonate with an 8-capsule serving; the bottle we price has a 4-capsule serving, so it may be a different version, and we do not count it. Life Extension and NOW were on none of the lists.
Is magnesium L-threonate worth the price?
For most people, no. It costs $2.15 or more for 300 mg of magnesium, against $1.10 for our glycinate pick, and its human trials are small and company-funded. It makes sense only if memory is your goal. L-threonate vs glycinate: the evidence.
Related magnesium guides
- L-threonate vs glycinate: the evidence and our verdict · magnesium for sleep
- All magnesium forms compared · magnesium glycinate prices · magnesium citrate prices
- Best magnesium overall · how much magnesium per day · magnesium guide
Look up a magnesium L-threonate label
Want to check a product that is not on this page? Search our supplement label lookup for the label facts filed for it with NIH.
Sources
- Prices: each brand’s own list price (its regular one-time price) for every size it sells, checked October 14, 2026. We quote no Amazon prices; Amazon is only where the buy links go.
- Labels: Life Extension Neuro-Mag (NIH label 328600, 144 mg per 3 capsules); NOW Magtein (NIH label 335276, 144 mg per 3 capsules); Double Wood (NIH label 315679, 144 mg per 4 capsules).
- Testing lists: NSF/ANSI 173, NSF Certified for Sport, USP Verified, Informed Choice and Informed Sport, searched October 14, 2026.
- Trial doses: Liu 2016 (PubMed 26519439), Hausenblas 2024 (39252819), Lopresti 2026 (41601871).
- NIH Office of Dietary Supplements. Magnesium fact sheet for health professionals (RDA and the 350 mg upper limit).
This page is for information. It is not medical advice.