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Magnesium citrate

Generic name: magnesium citrate [ mag-NEE-zee-um-SI-trate ]
Brand names: Citrate of Magnesia, Citroma Cherry, Citroma Lemon, ColonX, OneLAX Magnesium Citrate, Citroma
Dosage forms: oral capsule (100 mg; 125 mg; 133.3 mg), oral liquid (1.745 g/30 mL), oral tablet (100 mg), ... show all 4 dosage forms
Drug class: Laxatives

Medically reviewed by on Jan 8, 2024. Written by Cerner Multum.

What is magnesium citrate?

Magnesium citrate is used as a supplement to maintain adequate magnesium in the body.

Magnesium citrate is also used as a laxative to treat occasional constipation.

Magnesium citrate may also be used for purposes not listed in this medication guide.

Magnesium citrate side effects

Get emergency medical help if you have signs of an allergic reaction: hives, difficult breathing, swelling of your face, lips, tongue, or throat.

Magnesium citrate may cause serious side effects. Stop using magnesium citrate and call your doctor at once if you have:

Common side effects of magnesium citrate may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Follow all directions on the label and package. Use exactly as directed.

Before taking this medicine

Ask a doctor or pharmacist if magnesium citrate is safe to use if you have or have ever had:

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

How should I take magnesium citrate?

Use exactly as directed on the label, or as prescribed by your doctor.

Take with a full glass of water.

Shake the liquid medicine. Measure a dose with the supplied measuring device (not a kitchen spoon).

Magnesium citrate should produce a bowel movement within 30 minutes to 6 hours after you take the medicine.

Call your doctor if your symptoms do not improve after 7 days of treatment, or if the medicine produces no results. Not having a bowel movement after using a laxative may be a sign of a condition more serious than occasional constipation.

Store at cool room temperature away from moisture and heat.

Magnesium citrate dosing information

Usual Adult Dose for Constipation:

240 mL orally one time.

Usual Pediatric Dose for Constipation:

< 6 years: 0.5 mL/kg orally up to a maximum of 200 mL. May repeat every 4 to 6 hours until stools are clear.

6 to 12 years: 100 to 150 mL orally one time.

What happens if I miss a dose?

Magnesium citrate is used when needed. If you are on a dosing schedule, take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next dose. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking magnesium citrate?

Avoid taking any other medicines within 2 hours before or 2 hours after you take magnesium citrate. Laxatives can make it harder for your body to absorb other medicines you take by mouth.

What other drugs will affect magnesium citrate?

Other drugs may affect magnesium citrate, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you use.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.