Magnesium chloride is an inorganic compound consisting of one magnesium and two chloride ions. The compound is used in medicine as a source of magnesium ions, which are essential for many cellular activities. Magnesium dichloride hexahydrate has also been used as a cathartic and in alloys. Magnesium dichloride hexahydrate is a hydrate that is the hexahydrate form of magnesium dichloride. It is a hydrate, a magnesium halide and an inorganic chloride. It contains a magnesium dichloride.