Magnesium deficiency affects roughly half of US adults and contributes to sleep, cardiovascular, glucose, and cognitive issues. But the form matters enormously. Here's the 2026 guide to glycinate, threonate, malate, and which to take when.
Magnesium is the fourth most abundant mineral in the body and a cofactor for over 300 enzymatic reactions. Roughly 50% of US adults consume less than the RDA, and a substantial fraction have measurable subclinical deficiency. Low magnesium is associated with poor sleep, anxiety, hypertension, insulin resistance, atrial fibrillation, and accelerated cognitive decline. Correcting deficiency reliably improves multiple longevity-relevant biomarkers.
But magnesium supplementation is not as simple as buying any magnesium pill. The most common forms (oxide, citrate) have limited bioavailability and primarily produce GI effects. The forms that actually deliver magnesium to the tissues that need it (glycinate for muscle and sleep, threonate for brain, malate for energy production) are different products entirely.
This guide explains the major magnesium forms in 2026, what each one is good for, the brand picks, and the typical dosing.
Different magnesium salts have different absorption profiles, different tissue distribution, and different ancillary effects from the carrier molecule:
Adequate magnesium intake (RDA ~310–420 mg depending on age and sex) is associated with: