The Difference Between Magnesium Citrate and Magnesium Nitrate

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Don't let the similarity in their names fool you. Despite sharing every letter but one, magnesium citrate and magnesium nitrate are drastically different substances. While magnesium citrate is a common type of magnesium supplement often used as a laxative, magnesium nitrate is a toxic substance with agricultural, commercial and industrial uses. Consult your doctor before using magnesium citrate. If you plan to use magnesium nitrate, observe all handling and storage precautions.

Magnesium Citrate

Magnesium, an essential mineral, is crucial for the proper functioning of your heart and muscles. It also activates enzymes, balances and regulates your levels of calcium and other minerals, and contributes to the makeup of teeth and bones. Magnesium citrate is a formulation of magnesium carbonate combined with citric acid. Sold over the counter under various brand names, including Dulcolax, magnesium citrate functions as a hyperosmotic saline laxative that pulls water from tissues into the small intestine, stimulating elimination. It is often used to help patients empty their bowels before surgical procedures. The University of Maryland Medical Center notes magnesium citrate supplements may also be employed to treat magnesium deficiencies, high blood pressure and heart disease.

Usage and Considerations

The usual adult dosage of magnesium citrate is 8 oz., or 240 mL, in liquid form. To make liquid magnesium citrate more palatable, you can chill it or mix it with water or juice. The American Cancer Society advises drinking two glasses of cold water after taking it to replace fluids that will be lost. Common magnesium citrate side effects include upset stomach and diarrhea; if diarrhea is severe, an electrolyte imbalance can result. If you have symptoms of electrolyte imbalance, including confusion, weakness, irregular heartbeat, lightheadedness, fainting or shortness of breath, call your doctor. The website warns that you shouldn't take magnesium citrate for longer than one week. Don't use it if you have stomach pain, nausea or vomiting, or if you are pregnant or breast-feeding. Magnesium citrate can interact with other drugs. Consult your doctor before taking it.

Magnesium Nitrate

Magnesium nitrate is a hydrated form of nitromagnesite, a naturally-occurring mineral. The colorless, odorless, crystalline substance is used as a catalyst in the manufacture of petrochemicals and fireworks. Because it is water-soluble and supplies magnesium and nitrogen in a form easily accessible to plants, magnesium nitrate is also commonly employed as a fertilizer applied through irrigation. Other applications include use as an anti-corrosive agent to protect aluminum alloy in the aerospace industry, a preservative in food and a dietary additive for goats.


Magnesium nitrate is toxic, and can cause pain, irritation and redness of the skin and eyes. When inhaled, it causes coughing and shortness of breath. According to ICH World, you should don protective clothing -- including a long-sleeved coat or gown, gloves, goggles and a face mask -- before handling it. If magnesium nitrate gets on your skin, remove contaminated clothing and wash the area with soap and water for 15 minutes. If in your eyes, rinse for 15 minutes with cool water. If you have inhaled the dust, get to fresh air immediately. Taking magnesium nitrate internally causes nausea, stomach pain, faintness, shortness of breath, cyanosis -- or a blue tint to the skin -- and possible convulsions, stupor and death. If someone has ingested magnesium nitrate, ICH World advises inducing them to vomit and calling for emergency medical assistance. Magnesium nitrate must be stored in a cool, dry place.