Highly absorbable Magnesium Citrate – 400 mg of elemental magnesium to support energy, the nervous system, and muscle health NOW® Magnesium Citrate provides a highly absorbable form of magnesium in convenient vegetarian capsules. Magnesium is an essential mineral that supports energy production, nerve transmission, muscle function, and bone health. This formula uses fully-reacted magnesium citrate to ensure your body can absorb it effectively