Thompson's Organic Magnesium (174.9 mg elemental per tablet)
One tablet gives you 174.9 mg of magnesium. Only 8 % of it can be checked, and that part adds up. It costs $0.27 per 100 mg at the RRP.
can’t check: compound unclear no testing claim found
Compare with another productMagnesium blends (mixed compounds): all 7 compared
What the brand’s product page says
- Compound, as written
- “Magnesium amino acid chelate 805 mg, equiv. Magnesium 161 mg, Magnesium aspartate dihydrate 100 mg, equiv. Magnesium 7.5 mg, Magnesium orotate dihydrate 100 mg, equiv. Magnesium 6.4 mg, Total elemental Magnesium 174.9 mg”
- Compound per serve
- 1,005 mg in total across 3 compounds, listed below
- Magnesium per serve
- 174.9 mg
- Serve
- 1 tablet, 50 serves per pack, tablet
- Compounds listed
- Magnesium amino acid chelate: 805 mg (stated as 161 mg magnesium)
- Magnesium aspartate dihydrate: 100 mg (stated as 7.5 mg magnesium)
- Magnesium orotate dihydrate: 100 mg (stated as 6.4 mg magnesium)
- Register entry
- No AUST L number shown on the brand’s product page. A register search on 27 Oct 2026 didn’t reach its entry page. That doesn’t mean it’s unlisted.
- Read from
- Thompson's product page (opens in a new tab) (brand site), read 27 Oct 2026
How much of the compound is magnesium
Only part of each compound is magnesium. Here’s that share for each one. Some compounds come in several versions, for example with water in the crystals. Each version has its own share.
- Magnesium amino acid chelate: no standard share. With no amino acid named, it could be any of several compounds, each with its own share.
- Magnesium aspartate dihydrate: 7.5 % magnesiumThe brand’s product page names this version (“dihydrate”), so we use its share.
- Magnesium orotate dihydrate: 6.6 % magnesiumThe brand’s product page names this version (“dihydrate”), so we use its share.
Our maths
Magnesium amino acid chelate 805 mg → can’t work out: no standard share
Show the chemistry
The stated 161 mg from 805 mg would mean a share of 0.2.
Magnesium aspartate dihydrate 100 mg → about 7.5 mg magnesium ✓
Show the chemistry
100 mg × 0.0749 = 7.5 mgVersion used: magnesium aspartate dihydrate (Mg(C4H6NO4)2.2H2O, molar mass 324.53 g/mol, the hydrate commonly printed on Australian labels), share 0.0749. reference (opens in a new tab)
Other versions: magnesium aspartate, anhydrous 0.0842; magnesium aspartate tetrahydrate 0.0674.
Magnesium orotate dihydrate 100 mg → about 6.6 mg magnesium ✓
Show the chemistry
100 mg × 0.0656 = 6.6 mgVersion used: magnesium orotate dihydrate, share 0.0656. (worked out from standard atomic weights)
Other versions: magnesium orotate, anhydrous 0.0727.
Total: can’t be worked out
Do the figures agree?
Magnesium amino acid chelate: stated 161 mg; can’t check, no standard shareMagnesium aspartate dihydrate: stated 7.5 mg, our maths 7.5 mg (+0.1 %) ✓Magnesium orotate dihydrate: stated 6.4 mg, our maths 6.6 mg (-2.4 %) ✓parts add up to 174.9 mg = stated total 174.9 mg ✓checked: 13.9 of 174.9 mg = 8 %can’t check: compound unclear
We can’t tell. The brand’s product page calls the compound “Magnesium amino acid chelate”. That name covers several compounds, each with a different share of magnesium. So there’s no single number to multiply by, and we can’t check the stated 174.9 mg. This is common, and it isn’t a mark against the product. Why it matters to you: cost per 100 mg still works. It uses the stated magnesium figure. If the exact compound matters to you, ask the brand which amino acid it uses. 8 % of the magnesium could be checked; that part adds up.
Third-party testing
no testing claim found
No testing claim or certificate on the brand’s product page. That’s true of most products here, and it isn’t a mark against this one. The TGA doesn’t check each product before it goes on sale. If batch testing matters to you, ask the brand.
Our note: Neither the brand’s page nor the Chemist Warehouse listing mentions testing (both read 27 Oct 2026). A general look for HASTA (Human and Supplement Testing Australia) or Informed Sport listings or certificates found none; we haven’t yet looked by brand name.
Prices, and what the magnesium costs
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.
Price used: RRP $23.79 · 50 tablets · Chemist Warehouse · 27 Oct 2026.
$23.79 ÷ 50 serves = 47.6c a tablet47.6c ÷ 174.9 mg × 100 = $0.27 per 100 mg of magnesiumWe use the stated magnesium, not our maths, because that’s the figure you’re given. The price used is the lowest current RRP or regular price we’ve seen, at any shop. The list starts with the lowest current cost per 100 mg; earlier prices follow. Rows marked “Earlier observation (price type not recorded)” were seen up to 27 Oct 2026, before we switched to RRP. Some were sale prices. They stay here, greyed, as history, and no figure uses them.
| Retailer | Price type | Price and pack | Per serve | Per 100 mg | Seen | Note |
|---|---|---|---|---|---|---|
| Chemist Warehouse (opens in a new tab)price used above | RRP | $23.79 for 50 tablets | 48c | $0.27 | 27 Oct 2026 | Page prints "Don't Pay RRP $23.79" and '$14.79 Off RRP'; selling price shown was $9.00 (not used). |
| Chemist Warehouse (opens in a new tab)not used | Earlier observation (price type not recorded) | $9.00 for 50 tablets | not used | not used | 26 Oct 2026 | '$14.79 Off RRP', 'Don't Pay RRP $23.79'; sale price. |
Notes
Thompson’s page, whose footer names Homart Wellness AUST Pty Ltd as trade mark owner, matches the Chemist Warehouse listing’s panel. It also has vitamin D3, kelp (iodine) and vitamin B6; directions: 1 tablet twice daily.
Corrections
- 27 Oct 2026: Label source changed from the Chemist Warehouse listing (Chemist Warehouse listing, 50 tablets (opens in a new tab)) to the brand's own product page (Thompson's product page (opens in a new tab)), read 27 Oct 2026; a brand's page ranks above a retailer listing. Figures unchanged: chelate 805 mg (161 mg), aspartate dihydrate 100 mg (7.5 mg), orotate dihydrate 100 mg (6.4 mg), total elemental magnesium 174.9 mg. Compound wording updated to the brand page's panel text.
Sources we opened
- Chemist Warehouse listing, 50 tablets (opens in a new tab)
- Thompson's product page (opens in a new tab)
Added 26 Oct 2026. Figures last read 27 Oct 2026.