Can Gaviscon Help Reduce Your Heartburn?

How the Antacid Protects Against Acid Reflux

Gaviscon is an over-the-counter (OTC) antacid. It is used to treat or prevent heartburn in people with acid reflux or gastroesophageal reflux disease (GERD).

This article explains the benefits, ingredients, and usage of the antacid Gaviscon. It also describes the potential risks of Gaviscon and how to use the drug safely.

Gaviscon tablets

Verywell / Anastasia Tretiak

How Does Gaviscon Work?

Gaviscon contains ingredients that help neutralize stomach acids. Other ingredients create a foam barrier in the junction of the stomach and the esophagus or feeding tube. This barrier helps displace acid.


Studies have found that Gaviscon may reduce the symptoms of heartburn in people with acid reflux and GERD.

For milder cases, Gaviscon may be used on its own. For more severe cases, Gaviscon may be used with proton pump inhibitors (PPIs). These drugs reduce the production of stomach acids. PPIs like Nexium (esomeprazole) or Prilosec (omeprazole) are available over the counter, while others like pantoprazole require a prescription.

In addition to treating reflux, Gaviscon can prevent the onset of symptoms by reducing stomach acids after meals.


Gaviscon can be used on its own to treat occasional acid reflux. For more severe cases, including GERD, Gaviscon can be used with proton pump inhibitors (PPIs) like Prilosec and Nexium.

Ingredients and Product Details

Gaviscon is available as a tablet or liquid in both Regular-Strength and Extra-Strength formulations. The active ingredients aluminum hydroxide and magnesium carbonate help neutralize stomach acids. The amount of each ingredient, measured in milligrams (mg), varies by formulation.

 Type Active Ingredients
Gaviscon Regular-Strength (tablets) Aluminum hydroxide: 80 mg
Magnesium carbonate: 14.2 mg
Gaviscon Extra-Strength (tablets) Aluminum hydroxide: 160 mg
Magnesium carbonate: 105 mg
Gaviscon Regular-Strength (liquid) Aluminum hydroxide: 95 mg
Magnesium carbonate: 358 mg
Gaviscon Extra-Strength (liquid) Aluminum hydroxide: 254 mg
Magnesium carbonate: 237.5 mg

Gaviscon also contains sodium bicarbonate and alginic acid. The sodium bicarbonate creates the foaming action. The alginic acid gives the foam a sticky, gel-like consistency. This gel-like barrier is what displaces acid at the junction of the esophagus and stomach.

Gaviscon has a chalky consistency and comes in different artificial flavors, including mint, butterscotch, and orange.


Gaviscon contains two ingredients that neutralize stomach acid (aluminum hydroxide and magnesium chloride) and two ingredients that provide the foaming action (sodium bicarbonate and alginic acid).


Gaviscon comes as a chewable tablet or liquid. Both are taken by mouth and have different prescribing information.


  • Gaviscon tablets (Regular and Extra Strength): Take two to four tablets four times daily. Chew the tablets thoroughly and follow with a glass of water. Do not swallow the tablets whole. 
  • Gaviscon Regular Strength liquid: Take one to two teaspoons (5-milliliter spoonfuls) four times daily. Follow with a glass of water. Shake the bottle well before use.
  • Gaviscon Extra Strength liquid: Take one to two tablespoons (15-milliliter spoonfuls) four times daily. Follow with a glass of water. Shake well before use.

When to Take Gaviscon

Gaviscon should be taken after meals and at bedtime. Taking Gaviscon on an empty stomach may make it less effective.

What If I Take Too Much?

Gaviscon is unlikely to cause any harmful side effects. Taking too much could cause bloating and gas.

That said, you should avoid taking antacids for more than one to two weeks unless directed to by your healthcare provider.


Gaviscon tablets and liquids can be taken four times daily after meals and at bedtime. Follow with a glass of water. Read the product label to ensure the correct dose.

Special Precautions

Gaviscon is not for everyone. People who are taking certain medications or supplements or who have certain medical conditions should talk to a healthcare provider before using Gaviscon.

Before You Take Gaviscon

Before you take Gaviscon, make sure you are not allergic to any of the ingredients. Remember that Gaviscon and other antacids can mask the symptoms of certain medical conditions, some of them serious. If your heartburn doesn't get better after you've been taking Gaviscon for seven days, talk to your healthcare provider. 

Precautions With Other Medications

Gaviscon may interact with vitamin D and thyroid hormones, decreasing their absorption in the gut. To avoid interactions, let your healthcare provider know about any medications you take, whether they are prescription, over-the-counter, nutritional, herbal, or recreational.

Who Should Not Take Gaviscon?

Certain people may need to avoid Gaviscon or use it with caution. Before using Gaviscon, tell your healthcare provider if you have any of the following:

Gaviscon is also high in sodium, so you may need to avoid it if you are on a low-salt diet. People who are pregnant or breastfeeding are generally advised to avoid Gaviscon just to be safe.


Let your healthcare provider know if you have kidney disease, a peptic ulcer, difficulty swallowing, or an allergy to any of the ingredients in Gaviscon.

Possible Side Effects

Side effects of Gaviscon are uncommon. In fact, a 2014 study found no difference in side effects between people using Gaviscon and those given an inactive placebo.

If side effects occur, they tend to be mild but may include:

  • Indigestion
  • Nausea
  • Belching
  • Constipation
  • Dry mouth
  • Metallic taste
  • Diarrhea
  • Vomiting

Some of the side effects are due to the taste of Gaviscon, which some people describe as off-putting. Drinking a glass of water after a dose may help reduce nausea, indigestion and, belching.


Side effects from Gaviscon are uncommon. If they occur, they tend to be mild. Drinking a glass of water after a dose may reduce nausea, indigestion, and belching.


Gaviscon is a popular, over-the-counter antacid used to relieve heartburn in people with occasional acid reflux or GERD. It contains aluminum hydroxide and magnesium carbonate, which neutralize stomach acid, and sodium bicarbonate and alginic acid, which creates a protective foam barrier between the stomach and esophagus.

Gaviscon is available as a tablet or liquid. It can be taken four times daily after meals and at bedtime. Side effects tend to be mild and may include indigestion, nausea, and belching. Gaviscon should be used with caution in people with kidney disease, a peptic ulcer, or trouble swallowing.

Frequently Asked Questions

  • How quickly does Gaviscon work?

    Gaviscon may start working as soon as 10 minutes after you take it. The effects can last for up to four hours. In studies, the effects of Gaviscon tend to last longer than those of traditional antacids.

  • Can you take Gaviscon on an empty stomach?

    You should not take Gaviscon on an empty stomach. This is because the medicine will be passed out of your stomach within about 20 minutes of taking it. To ensure the greatest effectiveness, take Gaviscon after meals.

  • Are there any long-term effects of taking Gaviscon frequently?

    Gaviscon is probably safe to take long-term. Still, you should discuss your symptoms with your healthcare provider if they last longer than seven days. Long-term use may mask the symptoms of a more serious problem.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. National Medicine. GAVISCON- aluminum hydroxide and magnesium carbonate liquid label.

  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 inhibitorAliment Pharmacol Ther. 2016;43(8):899-909. doi:10.1111/apt.13567

  4. Galmiche JP, Bourreille A, Scarpignato C. Drug therapy of gastro-oesophageal reflux. In: Drug Therapy for Gastrointestinal and Liver Diseases. Boca Raton, Fla: CRC Press; 2019.

  5. National Health Service. Gaviscon (alginic acid).

  6. 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 diseaseAliment Pharmacol Ther. 2014;39(6):595-602

  7. Deraman MA, Abdul Hafidz MI, Lawenko RM, et al. Randomised clinical trial: the effectiveness of Gaviscon Advance vs non‐alginate antacid in suppression of acid pocket and post‐prandial reflux in obese individuals after late‐night supper. Aliment Pharmacol Ther. 2020;51(11):1014-21.