Antacid Refill

30 tablets
Relieves acid indigestion and stomach pains.
HeartburnUpset StomachConstipationGluten-Free
  • Magnesium Oxide 400 mg (241.3 mg Elemental Magnesium)

Compare to Magnesium Supplement

1 Pouch
30 day money-back guarantee | Free shipping over $45
  • 30 Antacid tablets in compostable refill pouch (municipal or industrial).

  • 1 Antacid magnetic label and drug facts booklet.

  • Batch-level quality verified medicine. 3rd party tested for allergens, carcinogens, gluten, and purity.

  • Profits go towards sustainable healthcare initiatives such as our plastic offset program and bulk sustainable packaging R&D.

Frequently Asked Questions


Cabinet Antacid is an over-the-counter (OTC) magnesium oxide supplement that can be used in three different ways:

  1. As an antacid. Magnesium oxide works to neutralize acid in the stomach to relieve symptoms of heartburn, acid indigestion, and upset stomach.

  2. As a laxative. Magnesium oxide can be used short-term as a laxative to help with occasional constipation. It works by promoting intestines to release water into the stool, which softens the stool and relieves constipation.

  3. As a dietary supplement. This product can be used as a dietary supplement to prevent or treat low magnesium levels in the blood. Magnesium is an important element required for normal bodily functions and plays a role in cells, bones, muscles, nerves, and the heart. Magnesium deficiency (or hypomagnesia) can occur with:

    • Diuretics (aka 'water pills' including furosemide, chlorthalidone, hydrochlorothiazide)

    • Unhealthy diet

    • Alcoholism

    • Severe diarrhea or vomiting

    • Uncontrolled diabetes and other chronic medical conditions

Fun fact! Magnesium oxide is occasionally used for migraine prevention in people who suffer from chronic migraine. It is also sometimes used to relieve muscle cramps in the leg (mixed data).

Take one (1) tablet of Cabinet Antacid twice a day as needed, or as directed by your doctor, for symptoms of acid indigestion or upset stomach. If you are taking this product as a magnesium supplement to ensure you are getting enough magnesium in your diet, check in with your doctor to see what dose is recommended for you. The general dose for low magnesium levels is one (1) to two (2) tablets daily.

Regardless of the reason you are taking Cabinet Antacid, do not take more than two (2) tablets in 24 hours or use the maximum dosage of this product for more than two weeks unless you are being monitored by a health care professional.

This product is not recommended for children under the age of 12, unless directed by a doctor. Cabinet Antacid should be stored away from young children.

In the case of an overdose, contact a Poison Control Center (1-800-222-1222) or seek medical attention immediately.

Stop using Cabinet Antacid and seek medical advice from a doctor if your symptoms get worse or last for more than two weeks. This may be a sign of something more serious.

Avoid taking Cabinet Antacid if you have any form of severe renal impairment or kidney failure (ESRD). Always avoid taking magnesium oxide if you have a history of hypersensitivity or severe allergy to the ingredient.

Before taking Cabinet Antacid, speak to your doctor if you are allergic to magnesium oxide or any other drugs. Many over-the-counter and prescription drugs may contain similar ingredients, so it may be best to have a health care professional go through your drug allergy history prior to using this supplement.

Magnesium oxide does have a few drug interactions, so it is recommended to check with your doctor or local pharmacist if you are taking:

  • Other antacids or laxatives

  • Anticoagulants, like warfarin

  • Aspirin

  • Diuretics ('water pills'), like furosemide or hydrochlorothiazide

  • Ulcer medication, like famotidine or cimetidine

  • Any other vitamins

Lastly, consult with your doctor prior to taking Cabinet Antacid if you have any form of heart disease, kidney disease, liver disease, gastrointestinal disease, or high blood pressure.

The use of magnesium oxide during pregnancy or lactation is generally considered to be safe. However, not all people and pregnancies are the same! Make sure to consult with a doctor or healthcare provider before using Cabinet Antacid.

In addition to its desired effects, Cabinet Antacid may cause some less desirable side effects. Everyone is different, so some people may experience no side effects at all, others may experience mild side effects, and a small number of people may experience rare or more serious adverse effects.

Some side effects of magnesium oxide include stomach upset and diarrhea. Taking Cabinet Antacid with food may help to reduce these side effects.This product may also cause elevated magnesium levels (hypermagnesemia), which can range from mild to severe. Symptoms of more severe hypermagnesemia include: nausea, vomiting, mental impairment, abnormally low blood pressure, flushing, headache, difficulty breathing, and shock. Some patients may experience side effects that are not on this list. Check in with your health care provider if you have questions or experience concerning side effects.

Although rare, seek medical attention immediately if you develop a serious allergic reaction to magnesium oxide. Signs of an adverse allergic reaction may include: hives, difficulty breathing, and swelling of your face, lips, tongue, or throat.

FAQs and Drug Facts Medically Reviewed by Joanna Tam, Healthcare and Content Manager