Do you find magnesium supplement labels confusing?
Founder of Clean Green Safe
You're not alone, and it's not your fault. Most labels show two different numbers, and only one of them tells you how much magnesium you're really getting. Here's how to find it.
The number that matters
Magnesium always comes joined to something else, like oxide, citrate or glycinate. The big number on the label is often the weight of the whole compound. What you want is the amount of magnesium itself.
Look for words like “equivalent to magnesium” or “elemental magnesium”. That’s the number to use.
For example: “Magnesium aspartate dihydrate 500 mg” sounds like a lot, but it’s only about 37.5 mg of magnesium.
Our mineral calculator works it out for you from the form on your label.
How much magnesium each form gives you
Taking magnesium glycinate or bisglycinate? Read how much magnesium you’re really getting, and the top-rated options in Australia.
- Magnesium oxide: about 60%
- Magnesium phosphate: about 21%
- Magnesium citrate: about 16%
- Magnesium aspartate: about 7.5%
- Glycinates and chelates: this varies, so check the label for the magnesium amount
Daily nutritional targets
- Women: 310 mg (19–30 years), 320 mg (31 and over)
- Men: 400 mg (19–30 years), 420 mg (31 and over)
From supplements, adults shouldn’t go over 350 mg a day. Magnesium from food doesn’t count towards this limit.
Three quick checks before you buy
- Find the magnesium amount, not the compound weight.
- Multiply it by the number of tablets you’ll take each day.
- Look for an AUST L or AUST R number. It shows the product is on the TGA register.
If you take other medicines, or you’re not sure magnesium is right for you, your pharmacist or GP is always happy to help.
Cassie is a registered pharmacist, a parent and the founder of Clean Green Safe. With a background in Australian supplement regulation across the TGA, FSANZ and NHMRC, she built Clean Green Safe to help people understand what’s really in their supplements, and how it all adds up across everything they take.
How Clean Green Safe can help
You don’t have to do the label maths yourself. Scan your magnesium supplement or enter its AUST L number, and Clean Green Safe works out the elemental magnesium for you, compares it with your daily target and checks it against the TGA register.
- STEP 1ScanScan the barcode or enter the AUST L number
- STEP 2CheckWe check it against the TGA register and Australian limits
- STEP 3SeeSee your grade and your daily totals across everything you take
Built by a registered pharmacist · Works in your phone’s browser
Magnesium reference data
Daily nutritional target
Reference type: RDI. Source: NRV Table 8.
Upper limit
Common forms
- magnesium oxide
- magnesium citrate
Basis form: elemental magnesium
Conversion factors
Reference details
Rated products containing this nutrient
Not medical advice. Reference values from NHMRC / NZ MoH Nutrient Reference Values.