Gaviscon for Heartburn

What You Need to Know About Gaviscon Antacid for Heartburn

Woman dropping liquid antacid medication into water
How do antacids such as Gaviscon work and what do you need to know?. Eric Audras/ONOKY/Getty Images

How is Gaviscon used for heartburn and what are the active ingredients? What precautions should you take with this medication and what are the possible side effects?


In addition to the acid-neutralizing ingredients found in most antacids (aluminum hydroxide and magnesium carbonate,) over-the-counter Gaviscon contains alginic acid and sodium bicarbonate. When taken as directed, GlaxoSmithKline, the drug's manufacturer, states the combination of the alginic acid and bicarbonate will create a a foam barrier which floats on the stomach acid.

This gel-like barrier displaces the acid pocket present at the junction of the espophagus and stomach and may help reduce the number of 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 for those who suffer with acid reflux. For mild disease, it may be used alone. For those with more severe reflux, it appears that Gavison may also be a helpful add-on for people who have an inadequate response to proton pump inhibitors. In addition to decreasing symptoms and the number of reflux episodes, Gaviscon appears to decrease postprandial (after eating) acid levels in theĀ esophagus as measured by a pH probe.

Ingredients and Product Details

Regular Strength Tablets (in each tablet)

  • Aluminum Hydroxide 80mg.
  • Magnesium Trisilicate 20mg.

    Extra Strength Tablets (in each tablet)

    • Aluminum Hydroxide 160mg.
    • Magnesium Carbonate 105mg.

    Regular Strength Liquid (in each tablespoon)

    • Aluminum Hydroxide 95mg.
    • Magnesium Carbonate 358mg.

    Extra Strength Liquid (in each teaspoon)

    • Aluminum hydroxide 254mg.
    • Magnesium carbonate 237.5mg.


    Gaviscon comes as a chewable tablet and liquid to take by mouth.

    Chew tablets thoroughly; do not swallow them whole. This is necessary for the medication to work properly. 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 1-2 weeks unless prescribed by your doctor.

    Special Precautions

    With any medication, the chance that it will be effective, as well as the chance that you may have adverse effects rests on how the medications is used in addition to its pharmacologic effects. To get the best results while minimizing side effects make sure to:

    • Tell your doctor and pharmacist if you are allergic to calcium carbonate. It's important that both your doctor and pharmacist have a thorough and up-to-date list of any and all allergies you have. Keep in mind that adverse reactions may sometimes 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/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 breast-feeding. If you become pregnant while using medications containing calcium carbonate, such as Gaviscon, call your doctor.

    Side Effects

    Side effects from Gaviscon are not common. In fact, a 2016 study looking at the effect on Gaviscon for heartburn found no difference in side effects between those using Gaviscon and those taking a placebo. Still, there are side effects that could 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


    Reimer, C., Lodrup, A., Smith, G., Wilkinson, J., and P. Bytzer. Randomised Clinical Trial: Alginate (Gaviscon Advance) vs. Placebo as Add-On Therapy in Reflux Patients with Inadequate Response to a Once Daily Proton Pump Inhibitor. Alimentary Pharmacology and Therapeutics. 2016 Feb 22. (Epub ahead of print).

    Thomas, E., Wade, A., Crawford, G., Jenner, B., Levinson, N., and J. Wilkinson. 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 Disease. Alimentary Pharmacology and Therapeutics. 2014. 39(6):595-602.

    Yuan, Y., Fang, J., Zou, D., Levinson, J., Jenner, B., and J. Wilkinson. 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 Sep 13. (Epub ahead of print).