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Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.



COMMON BRAND NAME(S): Mag-Ox 400, Magnacaps, Uro-Mag


Magnesium plays a critical role in the body. It is essential for normal functioning of nerves, muscles and cells. Magnesium supplements are used to treat or prevent low blood magnesium levels.



This medication may also be used to prevent certain types of kidney stones.

How To Use

Take this medication orally as directed. It is best taken with or just after a meal to improve absorption. Take each dose with a full glass of water. Swallow sustained release tablets whole. Do not crush or chew them.

Side Effects

This medication is generally well tolerated. Stomach upset, bloating, gas or diarrhea may occur, especially with higher doses. Notify your doctor if you experience: nausea, vomiting, any change in heart rate, flushing, faintness. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor your medical history, especially of: kidney disease, any allergies. This medication should be used as directed during pregnancy or while breast-feeding.

Drug Interactions

Tell your doctor of any over-the-counter or prescription medication you may take especially: digoxin, penicillamine, any antibiotics. Avoid taking any tetracycline or quinolone antibiotic within 1 to 2 hours of taking magnesium since it may interfere with the absorption of the antibiotic. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include slow heartbeat, flushing, severe drowsiness, dizziness, confusion, muscle weakness, and loss of consciousness.


Magnesium supplements are available in different forms which vary in the amount of medication they contain. Many are available without a prescription. Ask your doctor or pharmacist to help select the best product for you. Foods rich in magnesium include avocados, bananas, beans, grains, green vegetables, roasted peanuts. Follow any dietary guidelines recommended.

Missed Dose

If you miss a dose, take it as soon as remembered; do not take it if it is near the time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.


Store at room temperature between 59 and 86 degrees F (15 to 30 degrees C) away from heat and light. Do not store in the bathroom.