Magnesium citrate is a supplement that is commonly used as a laxative. A laxative is something that loosens stool (poop) so it’s easier for you to have a bowel movement. Magnesium citrate is the most commonly used magnesium salt supplement to treat constipation, a condition that makes it difficult to pass stool.

Magnesium citrate brings water into your intestines and stool, which makes the stool softer and easier to pass and increases the number of bowel movements. This makes it less painful to have a bowel movement and lowers your risk for straining and injury.

Magnesium citrate is considered the strongest osmotic (brings water into the body) option of all magnesium salt types, including magnesium oxide, magnesium hydroxide, and magnesium sulfate.

Magnesium citrate is available over-the-counter as a supplement that is taken orally (by mouth). It’s available as a liquid solution, powder, tablet, capsule, or gummy.

Form: The liquid solution is the form most commonly used to help with constipation. The other forms are more often used when looking to increase magnesium levels.

Dosage: The typical magnesium citrate dose for the liquid solution often ranges between 150-300 milliliters, taken as a single dose as needed. Research findings suggest a magnesium citrate dose of 11.3-17.45 grams can help treat constipation. However, the exact magnesium citrate dose you should take depends on the product you use and your age.

What to take or avoid with it: You should take magnesium citrate with a full glass of water. If you are taking other medications, take them at least two hours before or two hours after you take magnesium citrate. If you’re using a powder product, be sure to take the product within 36 hours of mixing the solution.

How long before you start feeling results: Magnesium citrate works within 30 minutes to six hours after taking one dose.

How long to use it for: You shouldn’t take magnesium citrate for longer than one week unless your doctor tells you to.

Osmotic laxatives like magnesium citrate are often considered the most effective supplements to treat constipation. However, there aren’t many studies that compare magnesium citrate to other commonly used over-the-counter and prescription laxatives in constipation. Research that has compared effectiveness shows that magnesium citrate is just as effective as other laxatives, including MiraLAX (polyethylene glycol).

Magnesium citrate is safe for most people to use. The most common side effects associated with magnesium citrate are:

• Diarrhea
• Stomach pain or discomfort
• Nausea and vomiting

Get immediate medical help if you experience serious side effects like:

Higher magnesium levels: If taken long-term, magnesium citrate may raise magnesium levels in your body. Researchers have found this might be less likely when the supplement is being used for constipation. Still, people with high magnesium levels or health conditions that affect magnesium (like kidney disease) should talk to their doctor about using magnesium citrate.

Medication interaction: Magnesium supplements can decrease how well your body absorbs and breaks down bisphosphonates, medications like Fosamax (alendronate) that are used to treat osteoporosis. Magnesium supplements can also affect how some antibiotics work, such as Cipro (ciprofloxacin), Levaquin (levofloxacin), and Vibramycin (doxycycline). To minimize interactions, take the medication or supplement at least two hours before or two to six hours after you take magnesium citrate.

Most people experience constipation at some point in their life.

Besides using magnesium citrate, you can prevent or treat constipation if you:

• Drink plenty of water and fluids.
• Exercise regularly.
• Train yourself to have a bowel movement at the same time every day.
• Use other laxative medications or supplements as prescribed or recommended by a doctor.
• Talk with your doctor to determine if any medications or supplements you’re taking can cause constipation.