Magnesium: which form?
Form changes absorption and tolerability, not whether the evidence holds. Here's the plain comparison.
| Form | What to know |
|---|---|
| Magnesium glycinate | well absorbed, gentle on the gut; popular for sleep |
| Magnesium citrate | well absorbed; mild laxative effect at higher doses |
| Magnesium oxide | poorly absorbed; mostly used as a laxative |
Elemental magnesium per 1000 mg of compound
The label on Magnesium gives the compound weight; your body absorbs the elemental magnesium content, which differs by compound form.
| Compound | Elemental magnesium | Note |
|---|---|---|
| Magnesium glycinate (bisglycinate) | ~140 mg elemental Mg per 1000 mg | Well tolerated; commonly used in sleep and anxiety trials. |
| Magnesium citrate | ~160 mg elemental Mg per 1000 mg | Higher elemental %; can be laxative at higher doses. |
| Magnesium oxide | ~600 mg elemental Mg per 1000 mg | High on paper but poorly absorbed — the label number does not reflect what your body uses. |
| Magnesium malate | ~150 mg elemental Mg per 1000 mg | |
| Magnesium threonate | ~80 mg elemental Mg per 1000 mg | Small elemental fraction; marketed for cognition on thin evidence. |