Milk of magnesia

Magnesium hydroxide is an inorganic compound with the chemical formula Mg(OH)2. As a suspension in water, it is often called milk of magnesia because of its milk-like appearance.

Suspensions of magnesium hydroxide in water, often called Milk of Magnesia, are used as an antacid to neutralize stomach acid, and as a laxative. The diarrhoea caused by magnesium hydroxide carries away much of the body’s supply of potassium, and failure to take extra potassium may lead to muscle cramps. That is why that equal concentrations of aluminium hydroxide are used with it to avoid unwanted laxative effects.