NF Supplements · Label Checker

Is your magnesium
the real deal?

Some brands add cheap magnesium oxide to make the number on the label look bigger. This checks the maths for you in a few seconds.

1

What’s in it?

Enter the BIG number(s) on the label — the weight of the magnesium ingredient. Not the smaller “Magnesium” number (that goes in Step 2).

Example label — which number goes where
Magnesium Bisglycinate the whole ingredient
1500 mg
This one → Step 1
of which Magnesium the real magnesium (“elemental”)
300 mg
This one → Step 2
2

How much magnesium does it promise?

This is the smaller number that just says “Magnesium” — the real magnesium your body gets (the label may call it “elemental”).

?
Result
Label promises
– mg
vs
Most it can really give
– mg
NF Supplements Magnesium Glycinate, 120 capsules

No buffering · No hiding

Magnesium you don’t have to second-guess

Our Magnesium Glycinate is 100% pure and unbuffered — no cheap magnesium oxide sneaked into the blend to pad the number. Run it through the calculator yourself.

  • Pure magnesium bisglycinate — zero oxide buffering
  • 3rd-party tested, every single batch
  • Gentle on the stomach and highly absorbable
Shop Magnesium Glycinate →

Not all magnesium is equal

A big number on the label isn’t the whole story. Some forms are packed with magnesium but barely absorb (that’s why the cheap ones get used for buffering). Gentler forms have less on paper but absorb far better.

How much magnesium it contains How well your body absorbs it

Absorption is a general guide from research — studies vary, and it also depends on the dose and the person. Content % comes from each compound’s molecular weight.

See the full data as a table
Elemental magnesium content (% by weight) and relative absorption, by magnesium compound.
Magnesium formElemental magnesium (% by weight)Relative absorption
Magnesium bisglycinate (glycinate)14.1%Excellent
Magnesium citrate16.2%Good
Magnesium malate15.5%Good
Magnesium chloride25.5%Good
Magnesium lactate12.0%Good
Magnesium taurate8.9%Good
Magnesium aspartate8.4%Good
Magnesium L-threonate8.3%Good
Magnesium gluconate5.8%Good
Magnesium orotate7.3%Okay
Magnesium ascorbate6.4%Okay
Magnesium carbonate28.8%Low
Magnesium sulfate20.2%Low
Magnesium hydroxide41.7%Low
Magnesium oxide60.3%Poor

Magnesium buffering: common questions

What does “buffered magnesium” mean?
Buffered magnesium is when a cheaper, magnesium-dense ingredient — usually magnesium oxide — is blended into a product to raise the elemental magnesium number on the label. A product might say “magnesium bisglycinate” but actually be bisglycinate mixed with magnesium oxide. The oxide is poorly absorbed, so you get a big number on paper but less usable magnesium.
How do I know if my magnesium is buffered?
Compare the elemental magnesium claimed on the label with the most the stated compound can provide. Magnesium bisglycinate is only about 14% elemental magnesium, so 1000 mg of pure bisglycinate can give at most ~141 mg. If the label claims more than the compound can physically provide, it has been buffered or mislabelled. This calculator does that maths for you in seconds.
How much elemental magnesium is in each type?
Approximate elemental magnesium by weight: magnesium oxide ~60%, hydroxide ~42%, carbonate ~29%, chloride ~26%, sulfate ~20%, citrate ~16%, malate ~16%, bisglycinate (glycinate) ~14%, lactate ~12%, taurate ~9%, aspartate ~8%, L-threonate ~8%, orotate ~7%, ascorbate ~6%, gluconate ~6%.
Which magnesium is best absorbed?
Chelated and organic forms — magnesium bisglycinate (glycinate), citrate, malate, taurate and L-threonate — are generally well absorbed and gentle on the stomach. Inorganic forms like magnesium oxide, carbonate and hydroxide have a high magnesium content but are poorly absorbed.
Is magnesium oxide bad?
Magnesium oxide is not dangerous, but it is poorly absorbed (studies suggest only a few percent) and can have a laxative effect. It is cheap and magnesium-dense, which is why it is often used to buffer products and inflate the elemental magnesium figure. If your goal is absorption, a chelated form like bisglycinate is usually the better choice.
How does the magnesium buffering calculator work?
Enter the type and amount of the magnesium compound (the big number on the label) and the elemental magnesium it claims (the smaller number). The calculator multiplies the compound amount by that compound’s known elemental percentage to find the most elemental magnesium that is physically possible. If the claim is higher than that, the product must be buffered with a denser magnesium source such as oxide.
Where can I buy pure, unbuffered magnesium?
NF Supplements Magnesium Glycinate is pure, unbuffered magnesium bisglycinate with no magnesium oxide added, and it is third-party tested for every batch.
Why this works. Magnesium is always stuck to something else — glycine, citric acid, oxide, and so on. So a pill is only part magnesium by weight. Magnesium bisglycinate is only about 14% magnesium. Magnesium oxide is about 60%. We work out the most magnesium your chosen form could possibly give. If the label promises more than that, the extra had to come from somewhere — usually cheap magnesium oxide.

These numbers are the best-case maximum for pure ingredients, so a “passes” result is a ceiling, not a promise. This is a helpful guide, not lab testing or medical advice.
NF Supplements — Natural Foundation