Magnesium Oxide Side Effects

Applies to magnesium oxide: oral capsule, oral tablet.

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

Stop using magnesium oxide and call your doctor at once if you:

• have rectal bleeding; or

• do not have a bowel movement after using magnesium oxide as a laxative.

Common side effects may include:

• nausea, vomiting;

• diarrhea; or

• stomach pain, loss of appetite.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For healthcare professionals

Applies to magnesium oxide: compounding powder, oral capsule, oral tablet.

Metabolic adverse events

• Frequency not reported: Hypermagnesemia, magnesium toxicity^[Ref]

Magnesium toxicity symptoms may include: hypotension, nausea, vomiting, facial flushing, urine retention, ileus, depression, lethargy, muscle weakness, respiratory depression, arrhythmia, cardiac arrest, coma, and death.^[Ref]

Gastrointestinal

• Frequency not reported: Diarrhea, nausea, abdominal cramping^[Ref]

See also:

Frequently asked questions

• When is the best time to take magnesium, morning or night?
• Should I take magnesium with or without food?
• Does magnesium help with restless leg syndrome (RLS)?
• Does magnesium help with headaches and migraines?
• Does magnesium help with weight loss?
• Can magnesium help with menopause symptoms?

Further information

Magnesium oxide side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer