Magnesium comes in several supplement forms, and the type you choose affects both absorption and side effects. The two most commonly recommended are glycinate and citrate.
Magnesium glycinate is bound to the amino acid glycine, is well absorbed, and is generally gentler on the digestive system — it’s often preferred for sleep, anxiety, or muscle-related use since it’s less likely to cause a laxative effect.
Magnesium citrate absorbs well too, but draws water into the intestines, which is why it’s commonly used as a mild laxative or for occasional constipation. At typical supplement doses it’s generally well tolerated, but higher doses are more likely to cause loose stools.
The Recommended Dietary Allowance for magnesium is roughly 310-420 mg per day for adults, depending on age and sex, and that total includes what you get from food. Most people don’t need to supplement at all if they eat a varied diet with leafy greens, nuts, seeds, and whole grains.
This article is for general informational purposes and isn’t a substitute for individualized medical advice. People with kidney disease or those taking certain medications should talk to a doctor before supplementing with magnesium.