Magnesium citrate is a magnesium preparation in salt form with citric acid in a 1:1 ratio (1 magnesium atom per citrate molecule). The name “magnesium citrate” is ambiguous and sometimes may refer to other salts such as trimagnesium citrate which has a magnesium:citrate ratio of 3:2.
Magnesium citrate is used medicinally as a saline laxative and to completely empty the bowel prior to a major surgery or colonoscopy. It is available without a prescription, both as a generic and under various brand names including Citromag and Citroma. It is also used in the pill form as a magnesium dietary supplement. It contains 11.23% magnesium by weight. Compared to trimagnesium citrate, it is much more water-soluble, less alkaline, and contains less magnesium.