Minerals
Magnesium Oxide
A cheap form with a high percentage of elemental magnesium but poor absorption, so most of it stays in the gut. That makes it effective as an occasional laxative or antacid, but a weak choice for genuinely raising magnesium levels.
Best for
Occasional constipation and lowest cost
Absorption
Low
Tolerability
Strongly laxative
Typical timing
Evening for sleep support; with food to reduce GI upset
How to take Magnesium Oxide
A typical dose of Magnesium: 200–400 mg elemental magnesium per day. Best timing: Evening for sleep support; with food to reduce GI upset. The form you choose mainly affects absorption and how easily it sits with your stomach, not the overall dose.