Is magnesium threonate worth it? What the 6–9× price actually buys

Magnesium L-threonate, sold under the ingredient name Magtein, is the most expensive magnesium form in our 30-product table. Here's what the label shows, what you pay per 100 mg of magnesium, and how much evidence sits behind the price.

Disclosure (Anzeige). The Payhip button goes to the Magnesium Decoder, a guide Renvo Life sells. We earn from that sale. It uses the same Anzeige / Werbung (paid link) label as our other paid links. No supplement brand paid to be mentioned. How we make money.

Not medical advice. This is a shopping and label guide.

What L-threonate is

L-threonate is magnesium bound to threonic acid. It's a patented form, marketed for the brain. By weight it's only about 7–8% magnesium, the lowest share of any common form (calculated from chemical formulas). Real products vary with water content: Magtein labels show 144 mg of magnesium per 2,000 mg, which is 7.2%.

The label math

Because so little of the compound is magnesium, threonate labels show big compound numbers. Nutricost's Magtein bottle says "2,000 mg" on the front. Its Supplement Facts panel shows 144 mg of magnesium from 2,000 mg of Magtein, in a 3-capsule serving. Doctor's Best Brain Magnesium lists 150 mg of magnesium from 2,085 mg of Magtein, also in 3 capsules. The number that counts is the "Magnesium" line, as our label math guide explains.

What it costs per 100 mg

Every price: brand store price, checked 21 Oct 2026, before shipping, tax or coupons. Serving sizes as printed on labels; not a suggestion to take that amount. The Qunol figure uses the 144 mg reading. At 114 mg it would cost more per 100 mg.

Per 100 mg of magnesium, threonate costs roughly 6–9 times a budget glycinate. All four threonate products use the same patented ingredient, yet the most expensive costs about 40% more per mg than the cheapest. Momentous is the only one we found in the NSF Certified for Sport directory (searched 21 Oct 2026).

How much evidence sits behind the price?

Less than the marketing suggests. The key brain-magnesium finding comes from a study in rats. We found no human study showing that other forms fail to reach the brain, or that threonate raises human brain magnesium more than other forms.

The human trials we found are small. One included 44 older adults and another 80 adults. In both, several authors worked for the companies developing or selling the ingredient. That doesn't make the results wrong, but it does mean they need independent confirmation. Our full guide sets out each marketing claim next to what the study actually measured.

The label conflict to watch

Qunol's Q-Mag page listed 144 mg of elemental magnesium in one place and 114 mg in another when we checked. If a brand's own page disagrees with itself, look at the Supplement Facts panel on the bottle you actually buy, or ask the brand.

So, is it worth it?

That depends on what you're paying for, and it's a decision to make with your clinician. What we can say is what the price buys: the same mineral, in a patented form, at a large premium per milligram, backed by early and industry-linked evidence. If you're comparing forms on cost, see magnesium cost per dose compared and glycinate vs citrate. To price a bottle of your own, use the magnesium cost per 100 mg calculator. The buffered glycinate check is the previous piece in this series, for when a cheaper bottle isn't the form it looks like.

A studio visit is a different bill

This table prices magnesium per 100 mg. It does not price a sauna or cold plunge session, and we don't publish session prices we haven't checked. The studio directory lists businesses whose own websites mention a sauna or cold plunge, checked 21 Oct 2026, with paid Featured spots labelled and free listings in A–Z order:

New York studios · Miami studios · San Diego studios · Phoenix studios · All studio cities

Related: Elemental magnesium label math · Magnesium cost per dose compared · Magnesium glycinate vs citrate · The Magnesium Decoder

Earlier in this series: buffered glycinate check

Next in this series (part 3 of 5): Premium vs budget magnesium: what the extra money buys →

Sources: NIH Office of Dietary Supplements, Magnesium fact sheet for health professionals; brand web stores, the NSF Certified for Sport directory and the NIH Dietary Supplement Label Database, checked 21 Oct 2026. Full citations for the threonate studies are in the Magnesium Decoder. No supplement brand paid to appear. Payhip buttons are labelled Anzeige because they go to a guide Renvo Life sells.

Free PDF guide: Biohacking on a budget

Last updated 21 Oct 2026