What is "magnesium sulfate"

n. The magnesium salt of sulfuric acid (chemical formula MgSO₄), commonly called Epsom salts.

n. a salt of magnesium

Magnesium sulfate is an inorganic salt ( chemical compound) containing magnesium, sulfur and oxygen, with the formula MgSO. It is often encountered as the heptahydrate sulfate mineral epsomite (MgSO·7HO), commonly called Epsom salt, taking its name from a bitter saline spring in Epsom in Surrey, England, where the salt was produced from the springs that arise where the porous chalk of the North Downs meets non-porous London clay. The monohydrate, MgSO·HO is found as the mineral kieserite. The overall global annual usage in the mid-1970s of the monohydrate was 2.3 million tons, of which the majority was used in agriculture.

Anhydrous magnesium sulfate is used as a drying agent. The anhydrous form is hygroscopic (readily absorbs water from the air) and is therefore difficult to weigh accurately; the hydrate is often preferred when preparing solutions (for example, in medical preparations). Epsom salt has been traditionally used as a component of bath salts. Epsom salt can also be used as a beauty product. Athletes use it to soothe sore muscles, while gardeners use it to improve crops. It has a variety of other uses: for example, Epsom salt is also effective in the removal of splinters.

It is on the WHO Model List of Essential Medicines, the most important medications needed in a basic health system.