Milk of magnesia is an oral suspension that contains hydrated magnesium carbonate. It is an over-the-counter medication intended for occasional or short-term use as an antacid or laxative.

Milk of magnesia is used to treat heartburn and constipation. It is a common over-the-counter (OTC) medication. Milk of magnesia, used as a laxative and antacid, brings rapid relief of symptoms.