what is magnesium oxide 400 mg used for

Magnesium oxide 400 mg is a mineral supplement used to prevent and treat low amounts of magnesium in the blood. It is also used to treat symptoms of too little magnesium such as heartburn, indigestion, constipation, and a magnesium deficiency. Magnesium oxide may also be used as a laxative for short-term, rapid emptying of the bowel (before surgery, for example) . Additionally, it is used as a dietary supplement when the amount of magnesium in the diet is not enough. Magnesium oxide is available without a prescription and comes in the form of tablets and capsules that are taken by mouth. It is important to follow the directions on the package or on the prescription label carefully and to ask a doctor or pharmacist to explain any part that is not understood. It is also important to note that magnesium oxide should not be used repeatedly as a laxative.