The common name for magnesium hydroxide is milk of magnesia. The compound has the chemical formula of Mg(OH)2. The name milk of magnesia is derived from the chemical's white, milk-like appearance.
Patented in 1818, milk of magnesia was sold for medicinal use as an antacid and laxative. It is also used in antiperspirant products and as a topical treatment for canker sores. Magnesium hydroxide has a molar mass of 58.31 grams per mole. It can be manufactured through a reaction of a solution of magnesium salts and a solution of ammonium hydroxide. It is found naturally in some minerals, such as chlorite.