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Treatment Name: Magnesium Citrate

Magnesium Citrate is a Supportive Care Therapy for Constipation

How does magnesium citrate work?

Magnesium citrate is designed to prevent your intestines from absorbing some of the water you drink. When extra water is kept within the intestines, it softens the stool and stimulates the intestines, which produces a bowel movement.

Goals of therapy:

Magnesium citrate is taken to relieve occasional constipation. It is commonly taken on an as needed basis with the goal of treating constipation.

Magnesium citrate is available as an over-the-counter (OTC) medication.


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How is magnesium citrate taken to treat constipation?

  • Usual starting dose: 1 half bottle (5 fluid ounces = 148 mL) to 1 full bottle (10 fluid ounces = 296 mL) by mouth once daily. Drink a full 8 ounce glass of water with each dose
    • It is often available in the following flavors: lemon, cherry, or grape
    • Do not take more than the recommended daily dose in a 24-hour period

Magnesium citrate is commonly taken at home on an as needed basis to treat constipation to maintain normal, regular bowel movements daily or every other day.

When dosed adequately, magnesium citrate generally induces a bowel movement in approximately 30 minutes to six hours. Do not take magnesium citrate for more than seven days without talking to your doctor.

May be stored at temperatures between 46-86
°F. Discard unused solution within 24 hours of opening bottle.

Side Effects

What are the most common side effects from magnesium citrate?

In the prescribing label information (magnesium citrate package insert), the most commonly reported side effects from magnesium citrate are shown here:

Taking too much magnesium citrate may cause cramping and loose stools or diarrhea. Use as directed by your Doctor.

Magnesium citrate should only be used in pregnant women if the potential benefits to the mother outweigh the potential risks to the unborn baby.

Note: The exact percentages of patients that will experience magnesium citrate side effects is unknown because it has been used under widely varying patient populations in a variety of clinical trials.

Watch videos on common magnesium citrate therapy side effects below

Side effect videos Side Effect Videos
PainPainNausea and VomitingNausea and Vomiting


How often is monitoring needed?

Labs (blood tests) are usually not necessary to start magnesium citrate therapy, but your blood magnesium may need to be checked if there is a concern that it may be too high.

How often is imaging needed?

Imaging may be checked if there is concern of a small bowel obstruction (SBO) or blockage. Imaging may include: Abdominal X-ray, or CT scan of the abdomen and pelvis.

How might blood test results/imaging affect treatment?

Depending upon the results, your doctor may advise to continue magnesium citrate as planned, add additional laxatives, place you on “bowel rest” (nothing by mouth until the obstruction clears), or switch to an alternative therapy for constipation.

Questions to Ask Your...

A better understanding of your treatments will allow you to ask more questions of your healthcare team. We then hope that with the answers, you will get better results and have greater satisfaction with your care. Because we know it's not always easy to know what questions to ask, we've tried to make it easy for you!

Choose any healthcare provider below to see common questions that you may want to ask of this person. Then, either print each list to bring to your clinic visits, or copy the questions and send them as a message to your healthcare team through your electronic medical record.

ChemoExperts Tips

What are the most important things to know about magnesium citrate?

  • Magnesium may decrease the absorption of certain antibiotics and other medications. Talk to your pharmacist to ensure that taking magnesium will not affect the effectiveness of any of your other medications
  • To reduce the chance of having loose stools and cramping, your Doctor or Pharmacist may advise that you take small sips of magnesium citrate over the course of several hours until the full recommend dose is taken
  • If you have kidney problems, talk to your doctor before taking magnesium citrate
  • To help improve taste, chill magnesium citrate in the refirgerator prior to drinking
  • If you are receiving chemotherapy, do NOT attempt to use an enema or suppository unless you have discussed this with your doctor. Use of enemas or suppositories could cause a tear in the rectum and may lead to a serious infection
  • Walking helps to stimulate the bowels to move stool down the intestinal tract. A diet high in fiber (found in fruits, vegetables, and whole grains) also helps to maintain a healthy colon (large intestine)
  • It is important to have regular bowel movements, usually once daily or every other day. Otherwise, your small bowel (intestine) may become blocked. Call your doctor if you have not had a bowel movement for 3 days or more, especially if you feel bloated. If you feel pain in your abdomen/belly, feel nauseated, or vomit at any point while constipated, call your doctor immediately
  • A pharmacist should ALWAYS review your medication list to ensure that drug interactions are prevented or managed appropriately

Patient Assistance & Co-payment Coverage

Patients under the age of 65 years, or those with private insurance plans:
If you have insurance and are looking for patient assistance or copay assistance for Magnesium Citrate, we have provided links that may help.

Visit our Patient Assistance page and click the links to various patient assistance programs for help paying for Magnesium Citrate. Depending upon your income, they may be able to help cover the cost of:

  • Magnesium Citrate

For Branded medications (may be available for generic medications too), check with the manufacturer to determine if a co-pay card is offered and if it could reduce your monthly copay.

  • If you are uninsured, check with the manufacturer to determine if you are eligible to receive medication at no cost.

Medicare and Medicaid patients (Patients 65 years or older):
The clinic providing treatment will likely pre-authorize medications and immune therapies such as Magnesium Citrate and are the best source to help you understand drug cost.

  • Ask to speak with a patient assistance technician or financial counselor at the clinic or hospital administering this therapy.

Created: March 31, 2020 Updated: April 17, 2020

What is Constipation?

Many treatment options for constipation exist. Watch our video to learn more about constipation and available treatments.