The Health Benefits of Magnesium Citrate

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Magnesium citrate is an osmotic laxative that comes in a liquid form. It is a combination of the element magnesium that is bound to citric acid. Magnesium citrate can be bought without a prescription in a drug store.

It may be used to treat occasional constipation and acid indigestion. When it is prescribed, it is used to help clear the large intestine of stool before a test. It may be used before a colonoscopy or an operation on the digestive system.

what is magnesium citrate

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This medication can also increase the amount of magnesium in the body. But other forms of magnesium are available which have the same effect and do not act as a laxative. Brand names of magnesium citrate that may be recommended for constipation or bowel preparation include:

  • Citrate of Magnesia 
  • Citroma
  • LiquiPrep

This article will discuss magnesium citrate, how it is used, the benefits of using it, and the side effects you may experience.

Health Benefits

Constipation is when you don't have regular bowel movements. It's a common problem that many adults experience from time to time. Some people find that constipation may even happen more frequently or become chronic.

Constipation can be uncomfortable. And in some cases, it can lead to problems such as hemorrhoids or anal fissures because of straining to pass hard stools. There are a variety of products available to treat constipation, including magnesium citrate.

Magnesium citrate works by pulling more water into the intestines. This process is called osmosis. When there is more water in the intestines, the stool becomes softer or even watery. It then becomes easier to pass.

Magnesium citrate is available over-the-counter in many drugstores under private and generic labels. But it should be used under a doctor's direction.

In most cases, using magnesium citrate once in a while to treat constipation is safe. However, using magnesium citrate on a long-term basis to treat constipation could result in other health problems. It’s recommended that magnesium citrate only be used for constipation after consulting with a doctor.

Possible Side Effects

Some of the negative effects that people experience with magnesium citrate include:

  • Abdominal discomfort
  • Nausea
  • Gas
  • Cramps

There are usually mild symptoms after taking magnesium citrate. But if severe symptoms occur, or a bowel movement doesn’t occur within about three hours after taking the magnesium citrate, it’s important to contact a doctor.

More serious side effects are uncommon but can include:

Most people don't have allergic reactions when they take magnesium citrate.

It’s important to let the doctor know about any other medications being taken, especially:

  • Digoxin (brand names: Cardoxin, Digitek, Lanoxicaps, and Lanoxin)
  • Sodium polystyrene sulfonate (brand names: Kalexate, Kayexalate, Kionex, and SPS)

You should also tell your doctor if you are taking antibiotics such as Vibramycin (doxycycline), Achromycin V or Sumycin (tetracycline), Minocin (minocycline), Levaquin (levofloxacin), or Cipro (ciprofloxacin). This is because magnesium citrate may make these medications less effective.

Usually, taking these medications two or three hours before taking the magnesium citrate can help avoid this problem. But check with a doctor or a pharmacist to be sure.

Using laxatives too much may have some harmful effects too. In particular, overuse of osmotic laxatives such as magnesium citrate may cause too much fluid loss. This can lead to electrolyte imbalances, especially in people who have other medical conditions such as kidney disease.

People who should avoid magnesium citrate include those who have:

Those who are dehydrated or on a low-magnesium diet should also avoid magnesium citrate.

Using magnesium citrate while pregnant or nursing appears to be safe. But check with your doctor before taking it.

If you accidentally take more than the recommended amount of magnesium citrate, call Poison Control at 1-800-222-1222.

Dosage and Preparation

The instructions and dosage for using magnesium citrate will be available on the bottle. Most often, the dosage for constipation in adults is 10 ounces. For children 6 to 12 years old, the dosage may be five ounces. For children under the age of 6, seek help from a pediatrician about constipation.

Drinking eight ounces of water after taking magnesium citrate is important. This is because it replaces the fluid loss from the body when more water is pulled into the intestines.

Because of the taste, some people find that magnesium citrate is easier to drink if it is chilled in the refrigerator for a while before drinking it. This product is a laxative, so it may cause diarrhea. Drinking plenty of fluids after taking it is important in order to prevent dehydration. 

When magnesium citrate is used to clear out the colon before a procedure, such as a colonoscopy, the doctor’s office will give instructions on when to start taking it. It is important to use the product according to the doctor's instructions. If the large intestine isn’t cleared of stool, the doctor may need to perform the test or procedure at a later date. Then you'll have to start the process all over again.

If there are any questions about using magnesium citrate, contact the doctor’s office. A pharmacist may also be able to help with general questions about this drug. Pharmacists can tell you how it should be taken. They will also let you know if there could be any potential side effects or interactions with other medications or supplements.


Magnesium citrate is a laxative that you can buy at a drug store without a prescription. It's used to treat constipation and acid indigestion. Doctors will also have you take it before a colonoscopy, The dosage for adults is usually 10 ounces, but instructions will be on the medicine bottle. Children 6 to 12 typically taking five ounces of magnesium citrate. Kids under the age of 6 should not take magnesium citrate without help from a pediatrician.

Let the doctor know if you're taking any other medications as magnesium citrate can make them less effective. Some people should avoid taking magnesium citrate if they have certain medical conditions. Talk with your doctor before deciding to take it.

A Word From Verywell

Constipation is common and is usually not a reason to visit a doctor unless it becomes chronic or it is causing significant discomfort or pain. For many people, the first instinct to resolve constipation is to turn to an over-the-counter laxative. And in most cases, laxatives are safe to use once in a while.

Magnesium citrate is mild when used in the recommended amounts. It may help you have a bowel movement. However a doctor sometimes prescribes larger amounts to clear out all the stool from your colon. When this happens, magnesium citrate can cause a lot of diarrhea.

Constipation that is occurring more frequently should be discussed with a doctor in order to talk about the most appropriate way to resolve it. It also helps your doctor find out if there is an underlying cause that needs treatment.

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