Milk of magnesia Mg(OH)2 is a saline-type laxative. The magnesia pulls a saline solution from the bloodstream; this excess fluid produces a flushing effect within the intestines. Available over-the-counter, it is most commonly used in alleviating constipation, but can also be used to relieve indigestion and heartburn, though the diarrhea side effect usually precludes this usage [1]. The most common brand name is Phillips' Milk of Magnesia. Chemically, milk of magnesia is a suspension of magnesium hydroxide in water at about 8% concentration by mass. The term "Milk of Magnesia" was first used to describe this mixture by Charles Henry Phillips in 1880.