Constipation can be very uncomfortable and even painful at times. Some people find relief from using magnesium citrate, a supplement that can relax your bowels and provide a laxative effect. Learn more about using magnesium citrate to treat constipation.


If you’ve gone more than three days without a bowel movement or your bowel movements have been difficult to pass, you may be constipated. Other symptoms of constipation may include:

  • having stool that’s lumpy or hard
  • straining during bowel movements
  • feeling like you can’t fully empty your bowels
  • needing to use your hands or fingers to manually empty your rectum

Many people experience constipation from time to time. It’s usually not a cause for concern. If you’ve been constipated for weeks or months, you may have chronic constipation. Chronic constipation can lead to complications if you don’t get treatment for it. These can include:

In some cases, chronic constipation is also a sign of a more serious health condition. Speak to your doctor if you experience chronic constipation or you notice sudden changes in your stool or bowel habits.

What causes constipation?

Constipation usually happens when waste moves through your system slowly. Women and older adults are at an increased risk of developing constipation.

The possible causes of constipation include:

  • a poor diet
  • dehydration
  • certain medications
  • a lack of exercise
  • nerve issues or blockages in your colon or rectum
  • problems with your pelvic muscles
  • certain health conditions, such as diabetes, pregnancy, hypothyroidism, hyperparathyroidism, or other hormonal disturbances

Tell your doctor if you’ve noticed changes in your stools or bowel habits. They can help you identify the cause of your constipation and rule out serious health conditions.

How can you use magnesium citrate to treat constipation?

You can often treat occasional constipation with over-the-counter medications or supplements, such as magnesium citrate. This supplement is an osmotic laxative, which means it relaxes your bowels and pulls water into your intestines. The water helps soften and bulk up your stool, which makes it easier to pass.

Magnesium citrate is relatively gentle. It shouldn’t cause urgency or emergency bathroom trips, unless you take too much of it. You can find it at many drug stores, and you don’t need a prescription to purchase it.

Your doctor may also prescribe magnesium citrate to help you prepare for certain medical procedures, such as colonoscopies.

Who can safely use magnesium citrate?

Magnesium citrate is safe for most people to use in appropriate doses, but some people should avoid using it. Speak with your doctor before taking magnesium citrate, especially if you have:

  • kidney disease
  • stomach pain
  • nausea
  • vomiting
  • a sudden change in your bowel habits that’s lasted over a week
  • a magnesium- or sodium-restricted diet

Magnesium citrate may also interact with certain medications. For example, if you’re taking certain medications to treat HIV, magnesium citrate can stop these drugs from working properly. Ask your doctor if magnesium citrate can interfere with any medications or supplements that you’re currently taking.

What are the side effects of magnesium citrate?

Although magnesium citrate is safe for most people, you may encounter side effects after using it. The most common side effects are mild diarrhea and stomach discomfort. You can also experience more serious side effects, such as:

  • severe diarrhea
  • severe stomach pain
  • blood in your stool
  • dizziness
  • fainting
  • sweating
  • weakness
  • an allergic reaction, which may cause hives, trouble breathing, or other symptoms
  • nervous system issues, which may cause confusion or depression
  • cardiovascular issues, such as low blood pressure or irregular heartbeat
  • metabolic issues, such as hypocalcemia or hypomagnesemia

If you experience any of these side effects, stop taking magnesium citrate and call your doctor right away.

What is the appropriate form and dosage?

Magnesium citrate is available as an oral solution or tablet, in which it’s sometimes combined with calcium. If you’re taking magnesium citrate for constipation, choose the oral solution form. People more commonly use the tablet as a routine mineral supplement to boost overall magnesium levels.

Adults and older children, age 12 years and older, can usually take up to 10 ounces (oz.) of magnesium citrate oral solution with 8 oz. of water. Younger children, age 6 to 12 years, can usually take up to 5 oz. of magnesium citrate oral solution with 8 oz. of water. Speak with your doctor to learn if these standard dosages are safe for you or your child.

If your child is 3 to 6 years old, ask their doctor about the right dosage for them. Magnesium citrate isn’t recommended for children under the age of 3 years old. If your baby or young child is constipated, your doctor can recommend other treatment options.

What is the outlook?

After taking magnesium citrate for constipation relief, you should expect the laxative effect to begin in one to four hours. Contact your doctor if you notice side effects or don’t experience a bowel movement. Your constipation may be a sign of a more serious underlying health condition.

Tips for preventing constipation

In many cases, you can prevent occasional bouts of constipation by adopting healthy lifestyle habits. Follow these tips:

  • Get regular exercise. For instance, incorporate 30 minutes of walking into your daily routine.
  • Eat a nutritious diet with a variety of fresh fruits, vegetables, and other fiber-rich foods.
  • Add a few tablespoons of unprocessed wheat bran to your diet. You can sprinkle it on smoothies, cereal, and other foods to increase your fiber intake.
  • Drink plenty of liquids, especially water.
  • Go to the bathroom as soon after you feel the urge to have a bowel movement. Waiting can cause constipation.

See your doctor if magnesium citrate and lifestyle changes don’t relieve your constipation. They can help you determine the source of your constipation and recommend alternative treatment options. Occasional constipation is normal, but sudden or long-lasting changes in your bowel habits may be a sign of a more serious underlying condition.