Magnesium oxide — uses, what it looks like & warnings

Uses

What the official label says Magnesium oxide is used for

The FDA label for Magnesium oxide states:

relieves: acid indigestion upset stomach

Purpose (from the over-the-counter label): Antacid

Read the label's “Indications and usage” section (verbatim)

relieves: acid indigestion upset stomach

Names & forms

Brand names, forms and strengths

Brand names (from RxNorm; not every brand is still sold): Mag-Ox 400, Magmilax, Phillips' Cramp-free, Uro-Mag.

Generic name: magnesium oxide · RxNorm ID (RxCUI): 6582

Forms and strengths of Magnesium oxide listed in RxNorm
Form	Strengths listed in RxNorm
Oral Capsule	140 MG, 400 MG, 500 MG
Oral Tablet	200 MG, 250 MG, 400 MG, 420 MG, 440 MG, 500 MG, 17900 MG, 276000 MG

Strengths are listed so you can recognise a product — not as dosing information. Only your prescriber can decide what is right for you.

Appearance

What Magnesium oxide looks like

magnesium oxide 400 mg
Westminster Pharmaceuticals, LLC

magnesium oxide 400 mg
Marlex Pharmaceuticals Inc

magnesium oxide 420 mg
Marlex Pharmaceuticals Inc.

magnesium oxide 400 mg
Kesin Pharma

Illustration based on label data — not a photo; appearance varies by manufacturer. Confirm with your pharmacist.

Appearance of Magnesium oxide products from DailyMed product data
Strength	Form	Colour	Shape	Size	Imprint	Score	Labeler
magnesium oxide 400 mg	tablet	white	round	11 mm	AM3	2	Westminster Pharmaceuticals, LLC
magnesium oxide 400 mg	tablet	white	round	11 mm	C14	1	Marlex Pharmaceuticals Inc
magnesium oxide 420 mg	tablet	white	round	11 mm	—	1	Marlex Pharmaceuticals Inc.
magnesium oxide 400 mg	tablet	white“White to off-white; speckled”	round	11 mm	MG	1	Kesin Pharma

From the product data in each manufacturer's label on DailyMed. Many companies make Magnesium oxide, so your medicine may look different from any shown here. If a pill looks unfamiliar, ask your pharmacist before taking it.

Read the label's “How supplied” section (verbatim)

Other Information Store at controlled room temperature 15° to 30°C (59° to 86°F). Tamper evident, do not use if imprinted safety seal under cap is broken or missing.

Safety

Important warnings for Magnesium oxide

Ask a doctor before use if you have kidney disease you are taking a prescription drug (antacids may interact with certain prescription drugs) you are pregnant or breast feeding. Do not take more than 2 tablets in a 24 hour period. May have a laxative effect. Keep out of reach of children.

Warnings and precautions (verbatim excerpt)

Ask a doctor before use if you have kidney disease you are taking a prescription drug (antacids may interact with certain prescription drugs) you are pregnant or breast feeding. Do not take more than 2 tablets in a 24 hour period. May have a laxative effect. Keep out of reach of children.

This is not a complete list of warnings or side effects. Read the full label and talk to your prescriber or pharmacist. To report a side effect to the FDA, use MedWatch.

Resources

If you were hurt at work

Whether a medicine is right for you is a decision for your prescriber. If you were injured on the job, these educational guides explain the next steps and who can help.

Magnesium oxide: uses, appearance and warnings