The Australian magnesium aisle is two shelves of marketing and a single column of chemistry. The order of operations almost no one walks in with: form first, then elemental dose, then everything else.
Glycinate (bisglycinate) is the answer for sleep, cramp, and anyone with a digestive system that argues back. It is roughly four times more bioavailable than oxide and gentle enough that none of our six panellists reported gut response at 300mg nightly. Citrate is the next step down — well-absorbed, mildly laxative, the right call if you are also chasing regularity. Oxide is the form in most supermarket multivitamins and the cheapest tablets at the chemist. It is the one the body absorbs least and the one the label leans on for the big-number front-of-pack.
The second trap is the multi-mineral blend. A glance at the back of any "stress complex" or "sleep complex" tub in Australia will usually show 60–100mg elemental magnesium per serve — a third of what a useful dose looks like. The brand has used the magnesium claim on the front and quietly underdosed the actual mineral so the formula can fit five other ingredients and a story. The Glow's filter — 250–350mg elemental in a single evening serve — is the cleanest way to throw out the underdosers in thirty seconds.
The Australian regulatory layer is worth one paragraph. Magnesium supplements sold here should carry an AUST L number on the label — listed medicines under the Therapeutic Goods Administration. AUST L is a self-assessment pathway, not a guarantee of efficacy, but it does require manufacturers to use only TGA-listed ingredients and to make claims within an approved set. Anything sold direct from a US site with no AUST L number is, technically, an unapproved therapeutic good in Australia. The four products we rank are all on the ARTG.
If you take one rule into the aisle: glycinate beats citrate beats oxide, 300mg elemental is the dose to look for, and the multi-mineral "sleep complex" is rarely worth what the front of the tub promises. If you want a single bottle: UltraMuscleze Night. If you want the cheapest version of the same idea: Bulk Nutrients glycinate.
— EA