Source Naturals Magnesium Malate is a compound of magnesium and Malic acid. It supports proper muscle function, cardiovascular health, and energy production. Malic acid is a natural fruit acid that is present in most cells in the body and is an intermediate in the Krebs cycle, where energy is captured during the metabolism of carbs and fats. Magnesium is an essential cofactor for over 300 enzymatic reactions in metabolism, ATP synthesis and energy production. Magnesium plays important roles in muscle relaxation, because of its function as a co-factor for enzymes and because of its ability to counterbalance calcium in the cell. Suggested Use is 1 to 3 tablets daily with meals. We have an in-house customer service team. Please contact us if you have any questions.