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Products / Magnesium

Magnesium aspartate

Aspartate is only about 7.5 % magnesium, so a 500 mg tablet gives you about 37 mg. The front number and the magnesium are far apart, so compare the panel figure.

See the product Work out any label

What it is

Magnesium bound to aspartic acid, an amino acid. It usually holds water, and more water means less magnesium:

  • dihydrate: about 7.5 %
  • tetrahydrate: about 6.7 %
  • dry: about 8.4 %

100 mg of magnesium takes about 1,335 mg of the dihydrate.

Names on Australian labels

  • Dihydrate or tetrahydrate: the water is named, so we use that share.
  • Magnesium aspartate or L-aspartate: water not stated. We use the dihydrate share and say so.
  • It’s also part of several blends.

What to check on the label

The magnesium figure is often in brackets, such as “(Magnesium 37.4 mg)”. Both figures printed? Multiply the compound by 0.075 for the dihydrate.

Why it matters to you: so little of it is magnesium that tablets can’t be compared by weight. Cost per 100 mg, below, puts it on the same scale as the rest. Whether it suits you is a question for a pharmacist.

Every aspartate product listed, by cost per 100 mg

All 1 product could be checked against its own figures.

Sorted by cost per 100 mg of magnesium, lowest first, until you sort. 1 product so far, added a few at a time, so not the whole market. No brand or retailer pays for inclusion, placement or marks.

Prices are the recommended retail price (RRP), or the regular shelf price where no RRP is shown. Sale and member prices aren’t used, so you may pay less.

How to read this list

“Label says” and “Our maths” are the magnesium you actually get per serve, not the compound weight. Labels call it elemental magnesium. “Cost per 100 mg” is what that magnesium costs, so small and large doses compare fairly.

  • Sort by cost per 100 mg to see what the magnesium itself costs.
  • Open a form page to compare like with like.
  • Tick two products to see them side by side, or open one to see the working.
Magnesium aspartate: stated magnesium, our maths, whether it adds up, testing and cost per 100 mg of magnesium, lowest cost first
Line Product Form Label says Our maths Adds up? Testing Cost per 100 mg of magnesium Cost per serve Price used Compare
1 Blackmores Magmin 500mgAspartateOnly aspartate here; figures add up; AUST L 220238; 1 tablet a serve aspartate 37.4mgper brand page: the brand’s product page 37.5mg500 × 0.0749 = 37.5 adds up no testing claim found $0.54 20c a tablet RRP $50.49 · 250 tabletsChemist Warehouse · 27 Oct 2026

“Label says” is the magnesium per serve from the source we read: the pack, the brand’s page or a shop listing. “Our maths” is the compound weight × its share of magnesium. “Adds up” means the two are within 15 %. Cost per 100 mg uses the stated magnesium and each shop’s newest RRP or regular shelf price. It shows the lowest. “Price used” is that price, with its pack and date. We don’t use sale or member prices. No RRP or regular price yet? Then there’s no cost, and the product sorts last. Prices older than 35 days say “may have changed”. What the marks mean. How we work out each figure.

Blends that include aspartate

They’re all on the blends page. Each product page shows what each part gives.

See also which magnesium is which, the calculator and the full table.