Magnesium Citrate


Magnesium citrate is used to treat occasional constipation on a short-term basis.

Magnesium citrate is in a class of medications called saline laxatives. It works by causing water to be retained with the stool. This increases the number of bowel movements and softens the stool so it is easier to pass.

Side Effects Of Magnesium Citrate

Magnesium citrate may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • loose, watery, or more frequent stools

Some side effects can be serious. If you experience any of these symptoms, stop taking magnesium citrate and call your doctor immediately:

  • blood in stool
  • unable to have a bowel movement after use

Magnesium citrate may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

Warnings & Precautions

Before taking magnesium citrate:

  • tell your doctor and pharmacist if you are allergic to magnesium citrate, any other medications, or any of the ingredients in magnesium citrate preparations. Ask your pharmacist or check the product label for a list of the ingredients.
  • tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • if you are taking other medications, take them at least 2 hours before or 2 hours after taking magnesium citrate.
  • tell your doctor if you have stomach pain, nausea, vomiting, or a sudden change of bowel habits lasting more than 2 weeks. Tell your doctor if you are on magnesium or sodium-restricted diet. Also, tell your doctor if you have or have ever had kidney disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking magnesium citrate, call your doctor.

Magnesium Citrate Dosage

Magnesium citrate comes as a powder to mix with a liquid and as a solution (liquid) to take by mouth. It is usually taken as a single daily dose or divide the dose into two or more parts over one day. Do not take it for more than 1 week, unless your doctor tells you to do so. Magnesium citrate usually causes a bowel movement within 30 minutes to 6 hours after taking it. Follow the directions on your product label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take it exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Take the liquid product with a full glass (8 ounces [240 milliliters]) of liquid.

To prepare the powder for solution, mix the powder with 10 ounces (296 milliliters) of cold water or other liquids and shake or stir the mixture thoroughly. If needed, refrigerate the solution after mixing it, but mix it again before use. If the oral solution mixture is not used within 36 hours after preparation, dispose of the mixture. Be sure to ask your pharmacist or doctor if you have any questions about how to mix or take this medication.
Ask your pharmacist or doctor for a copy of the manufacturer’s information for the patient.


Keep all appointments with your doctor.

Ask your pharmacist any questions you have about magnesium citrate.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.