Magnesium: do you need it, and which one?

Checked 25 October 2026 · labels from NIH's public label database, January 2026 release

The short answer

NIH lists 1,414 magnesium labels on the US market, which make up 1,367 products. Only 15 of those products are third-party tested: an outside lab's seal on the label, or the product's name on that lab's own list.

6 of them pass all three checks: third-party tested, none of the additives we check for, and a form an expert we quote prefers.

Source: NIH's public label database, 11 January 2026 release; checks by Decode, 25 October 2026

Which magnesium is third-party tested?. Third-party testing, additives and form, as printed on the labels of BulkSupplements.com · Magnesium BHB Powder, Bluebonnet · Simply Calm Powder Cherry Flavor, Douglas Laboratories · Magnesium/Potassium Aspartate, Solgar · Calcium Magnesium plus Zinc, The Vitamin Shoppe · Magnesium Glycinate 400 mg.

From every label to the ones that pass

  1. Magnesium products on the US market (NIH) 1,367
  2. Third-party tested 15
  3. …and none of the additives we check for 14
  4. …and a form an expert we quote prefers 6
The top bar is every magnesium product on the US market that NIH lists, from every brand. Only 15 of those products are third-party tested.

Source: NIH's public label database, 11 January 2026 release; checks by Decode, 25 October 2026

Do you need magnesium?

Start with your blood test. The number to look at is your Magnesium.

What was said about that number:

“…normal quote normal serum magnesium levels are about 1.8 to 2.3 but I think anything under two is linked to increased health risks and Optimum level should be over two so if you're getting a serum magnesium it should be over two”

“…and magnesium 300 to 500 milligrams daily”

See what your Magnesium result means

Which magnesium products pass all three checks?

Third-party tested, none of the additives we check for, and a form an expert we quote prefers. Sizes of one product are shown once.

Compare up to five brands side by side

What was said about each form of magnesium

glycinate named as preferred

“…these include magnesium citrate magnesium glycinate magnesium tarate these indicate um magnesium malate is also in there these organic salt forms of magnesium are generally more bioavailable”

carbonate named as preferred

“…you want magnesium carbonate. It's also worth noting magnesium carbonate more fully absorbed than mag oxide, citrate, or glycinate”

citrate named as preferred

“…these include magnesium citrate magnesium glycinate magnesium tarate these indicate um magnesium malate is also in there these organic salt forms of magnesium are generally more bioavailable”

threonate named as preferred

“…magnesium bisclycinate and magnesium threonate both have transporter systems that allow them to readily cross the blood-brain barrier”

citrate (for sleep) spoken against

“There are other forms of magnesium, magnesium citrate, which has other functions. Actually, magnesium citrate is a fairly effective laxative, not known to promote sleep and things of that sort”

threonate (for meeting daily needs) spoken against

“…magnesium threonate is not the best option for meeting daily magnesium needs it shouldn't be included as contributing to your recommended daily allowance of magnesium”

Brands that make magnesium

NIH lists 398 brands that make magnesium. This list shows each brand with a third-party tested product, plus each brand with its own page here.

Source: NIH's public label database, 11 January 2026 release; checks by Decode, 25 October 2026

Common questions

What counts as third-party tested?

A seal from an outside lab that tests what is inside, such as USP Verified or NSF Certified for Sport, or the product's name on that lab's own list, such as IFOS for fish oil. A badge about sourcing, diet or the factory does not count, because it does not test what is inside.

Does no seal mean a product failed a test?

No. It means the label shows no third-party test, and no testing lab's list we read (BSCG, IFOS, IGEN, IKOS, Informed Choice, Informed Sport) names the product. A brand can test privately. This page shows what the label and the lists show.

Which magnesium should I take?

That depends on your blood test. This page shows the label checks anyone can see.

Where does the label data come from?

The NIH Dietary Supplement Label Database, which is public domain. We read the file dated 11 January 2026. Brands change labels, so check the one you have.

Our method

Third-party tested
A seal from an outside lab that tests what is inside, printed on the label, or the product's name on that lab's own list.
Additives
Each other ingredient on the label, checked for artificial coloring, titanium dioxide, hydrogenated oil and BHA/BHT preservative, after a physician spoke against dyes, fillers and preservatives on video.

“…that are at the right Doses and that are effective and that don't have a lot of additives and fillers and preservatives and chemicals and dyes”

Form
The form printed on the label. When an expert we quote has talked about that form, the speech bubble next to it says where they stand. Open it to see what they said.
One product, many labels
Label versions that share a UPC count as one product. The newest label is the one shown.
Dose
The amount is shown as printed. Whether it suits you depends on your blood test.