Magnesium May Not Reach Your Brain, Despite Supplement Label Promises

Magnesium is essential for cells and neurons, but taking extra does not guarantee better function or mean it reaches the brain. The article says claims that particular supplements deliver magnesium to targeted organs go beyond what current human evidence can show.

Absorption depends on the dose, food in the stomach and existing magnesium levels, and larger doses are absorbed less efficiently. Magnesium oxide, common in cheaper pills, dissolves poorly and can mainly act as a laxative; citrate has shown higher bioavailability in laboratory tests. A rat study found brain and memory effects from magnesium L-threonate, but small human trials have limitations and did not measure magnesium in the brain; some were also linked to supplement makers.