Using Gaviscon for Heartburn

How the Antacid Protects You From Acid Reflux

Gaviscon tablets

Verywell / Anastasia Tretiak

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Gaviscon is an over-the-counter (OTC) antacid with ingredients that create a foam barrier that protects the junction of the esophagus and stomach. Learn how it works to prevent or relieve the symptom of heartburn and what precautions you should take with this medication.


In addition to the acid-neutralizing ingredients found in most antacids (aluminum hydroxide and magnesium carbonate), Gaviscon contains alginic acid and sodium bicarbonate. The combination of alginic acid and bicarbonate creates a foam barrier that floats on the stomach acid. This gel-like barrier displaces the acid pocket present at the junction of the esophagus and stomach and may help reduce reflux episodes. It may also provide longer-lasting action against heartburn in people with gastroesophageal reflux disease (GERD).


Several studies have found that Gaviscon may reduce the symptoms of heartburn in people who have acid reflux. For mild conditions, it may be used alone. For those with more severe reflux, Gavison may be a helpful add-on for people who have an inadequate response to proton pump inhibitors. In addition to decreasing symptoms and number of reflux episodes, Gaviscon appears to decrease postprandial (after-eating) acid levels in the esophagus as measured by a pH probe.

Ingredients and Product Details

Regular Strength Tablets (in each tablet)

  • Aluminum Hydroxide 80 milligrams
  • Magnesium Trisilicate 20 milligrams

Extra Strength Tablets (in each tablet)

  • Aluminum Hydroxide 160 milligrams
  • Magnesium Carbonate 105 milligrams

Regular Strength Liquid (in each tablespoon)

  • Aluminum Hydroxide 95 milligrams
  • Magnesium Carbonate 358 milligrams

Extra Strength Liquid (in each teaspoon)

  • Aluminum hydroxide 254 milligrams
  • Magnesium carbonate 237.5 milligrams


Gaviscon comes as a chewable tablet or liquid to take by mouth. For the medication to work properly, you need to chew the tablets thoroughly and you should not swallow them whole. Drink a full glass of water after taking the tablets. Shake the oral liquid well before each use to mix the medicine evenly. The liquid may be mixed with water or milk.

Follow the directions on the package label or on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take aluminum hydroxide and magnesium antacids exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Do not take antacids for more than one to two weeks unless prescribed by your doctor.

Special Precautions

Take these precautions to get the best results and minimize side effects:

  • Tell your doctor and pharmacist if you are allergic to calcium carbonate and about any other allergies. Adverse reactions may occur due to the inactive rather than the active ingredients in a medication.
  • Tell your doctor and pharmacist what medications you are taking. It's important to list not only your current prescription medications, but any nonprescription medications, vitamins, or nutritional or herbal supplements you are taking. Depending on your other medications, your doctor will be able to tell you whether you can take antacids with these medications, and if so, the best time of day to use the medication. For many medications, it's recommended to wait at least two hours after taking an antacid in order to ensure absorption of the other drug.
  • Tell your doctor if you have or have had kidney disease or stomach problems.
  • Tell your doctor if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while using medications that contain calcium carbonate, such as Gaviscon, call your doctor.

Side Effects

Side effects of Gaviscon are not common. In fact, a 2016 study looking at the effect of Gaviscon for heartburn found no difference in side effects between those using Gaviscon and those taking a placebo. Still, some side effects may rarely occur. Tell your doctor if any of these symptoms are severe or do not go away:

  • Upset stomach
  • Vomiting
  • Stomach pain
  • Belching
  • Constipation
  • Dry mouth
  • Increased urination
  • Loss of appetite
  • Metallic taste
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Article Sources
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  1. U.S. National Medicine. GAVISCON- aluminum hydroxide and magnesium carbonate liquid label. Updated December 22, 2017.

  2. Yuan YZ, Fang JY, Zou DW, Levinson N, Jenner B, Wilkinson J. Alginate-Antacid (Gaviscon Double Action) Chewable Tablets Reduce Esophageal Acid Exposure in Chinese Patients with Gastroesophageal Reflux Disease and Heartburn Symptoms. Journal of Digestive Diseases. 2016;17(11):725-734. doi:10.1111/1751-2980.12406

  3. Reimer C, Lødrup AB, Smith G, Wilkinson J, Bytzer P. Randomised Clinical Trial: Alginate (Gaviscon Advance) vs. Placebo as Add-on Therapy in Reflux Patients with Inadequate Response to a Once Daily Proton Pump InhibitorAlimentary Pharmacology & Therapeutics 43, no. 8 (2016): 899-909. doi:10.1111/apt.13567

  4. GlaxoSmithKline. GAVISCON® LIQUIDS.

  5. Thomas E., Wade A., Crawford G., Jenner B., Levinson N., Wilkinson J. Randomised Clinical Trial: Relief of Upper Gastrointestinal Symptoms by an Acid Pocket-Targeting Alginate-Antacid (Gaviscon Double Action) - A Double-Blind, Placebo-Controlled, Pilot Study in Gastro-oesophageal Reflux DiseaseAlimentary Pharmacology and Therapeutics. 2014. 39(6):595-602