Mylanta: Uses and Side Effects

Mylanta liquid

Verywell / Anastasia Tretiak

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Mylanta is a nonprescription brand of antacid used to treat symptoms of heartburn, acid reflux, indigestion, and stomach upset.

There are several available formulations of Mylanta that may contain aluminum hydroxide and magnesium hydroxide or calcium carbonate. Mylanta gas preparations contain simethicone, which can be helpful in treating intestinal gas.

Mylanta Uses

Mylanta antacids may be used to treat symptoms caused by gastrointestinal conditions such as:

Mylanta may contain a combination of aluminum hydroxide, magnesium hydroxide, or calcium carbonate. These ingredients work by reducing acid in the stomach. Some mylanta formulations also contain simethicone, which reduces gas.

How Fast Does Mylanta Work?

Mylanta is fast-acting and should start to provide relief within a few minutes.

Mylanta Products and Ingredients

The Mylanta product line changes over the years and it is important that you read the product labeling and instructions carefully so you understand which product you are using. You may have older products in your home that differ from the currently available formulations.

  • Mylanta Maximum Strength Liquid Antacid/Anti-Gas has active ingredients of aluminum hydroxide, magnesium hydroxide, and simethicone. It may be used for heartburn, acid indigestion, and gas. It comes in a couple of flavors.
  • Mylanta Tonight Liquid Antacid/Anti-Gas has active ingredients of calcium carbonate, magnesium hydroxide, and simethicone. It is made in a honey chamomile flavor that you may find soothing but it does not produce drowsiness. It is used for heartburn, acid indigestion, and gas.
  • Mylanta Gas Minis are chewable tablets in fruit or mint flavors with the active ingredient of simethicone. They are used to relieve gas.

Previously marketed formulations had various combinations of aluminum hydroxide, magnesium hydroxide, calcium carbonate, and simethicone. They included liquids, tablets, gel caps, chewable tablets, and chewable softgels, including some labeled for children.

Using Mylanta Products

Mylanta liquids should be shaken well before each use to mix the medicine evenly. To reduce the chalky taste, you can mix the liquid with water or milk. Be sure to note how much you should take based on age and don't exceed the maximum dose per day. The products come with a dosing cup that should be cleaned with warm water and mild dish soap after each use.

Chewable tablets should be chewed slowly and thoroughly. They are less effective if swallowed whole. Drink a full glass of water after taking the tablets.

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

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

Mylanta is designed to be used for the short-term control of minor symptoms. If your symptoms persist or worsen make sure to see your healthcare provider medication should only be used for an extended period of time under the careful guidance of a healthcare provider.


Before taking Mylanta:

  • Tell your healthcare provider and pharmacist if you are allergic to aluminum hydroxide and magnesium hydroxide antacids, and also any other allergies you have. There may be inactive ingredients in products that you are allergic to in addition to the active ingredients.
  • If you are on a magnesium-restricted diet, discuss the use of Mylanta antacid products with your healthcare provider as the antacid formulations usually contain magnesium.
  • Mylanta may interfere with certain medications. When using antacid products, tell your healthcare provider and pharmacist what prescription and nonprescription medications you are taking, especially aspirin, Lanoxin (digoxin), Valium (diazepam), Diflucan (fluconazole), Didronel (etirdronate), Dilantin (phenytoin), tetracycline antibiotics, and vitamins. Your healthcare provider will be able to tell you whether you can take antacids with these medications, and if so, whether you can do so at the same time, or take the medications at a different time. For example, you may need to delay taking other medications for two hours after taking an antacid. Calcium may decrease the effectiveness of other medications.
  • Tell your healthcare provider if you have or have ever had stomach problems or kidney disease.
  • Tell your healthcare provider if you are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while taking aluminum hydroxide and magnesium hydroxide antacids, call your healthcare provider.
  • Check the ingredients on other medications you are taking. Other medications may contain the same ingredients, and using both products may result in an excess dose.

Possible Side Effects of Mylanta

Although side effects from aluminum hydroxide, magnesium hydroxide or calcium carbonate in Mylanta are not common, they can occur. Simethicone does not usually cause side effects. Tell your healthcare provider if any of these symptoms are severe or do not go away:

  • Upset stomach
  • Vomiting
  • Stomach pain
  • Belching
  • Constipation or diarrhea
  • Dry mouth
  • Increased urination
  • Loss of appetite
  • Metallic taste
  • Unusual tiredness
  • Muscle weakness

A Word From Verywell

The occasional use of antacids can help give you symptom relief, but these products don't treat the underlying causes of your discomfort. But if you find yourself needing to use them regularly for heartburn or indigestion you should see your healthcare provider.

Conditions with these symptoms, such as gastroesophageal reflux disease (GERD), can have serious complications when not treated effectively. Your healthcare provider can advise you on more effective treatment.

Frequently Asked Questions

  • How long should I take Mylanta?

    Antacids like Mylanta are short-term medications that shouldn't be taken for longer than one or two weeks, unless a healthcare provider has instructed otherwise.

  • Is Mylanta safe to use while pregnant?

    In most cases, Mylanta should be safe to use to treat heartburn during pregnancy. However, it is still a good idea to speak with your healthcare provider about it beforehand.

4 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. Infirst Healthcare, Inc. Mylanta Maximum Strength Liquid Antacid/Anti-Gas.

  2. Infirst Healthcare, Inc. Mylanta Tonight Liquid Antacid/Anti-Gas.

  3. Infirst Healthcare, Inc. Mylanta Gas Minis.

  4. Cleveland Clinic. Medicine guidelines during pregnancy. Reviewed January 1, 2018.

Additional Reading
  • MedlinePlus, National Institutes of Health U.S. National Library of Medicine. Aluminum Hydroxide and Magnesium Hydroxide. Revised May 15, 2019.

  • MedlinePlus, National Institutes of Health U.S. National Library of Medicine. Calcium Carbonate. Revised September 15, 2015.

  • MedlinePlus, National Institutes of Health U.S. National Library of Medicine. Simethicone. Revised February 15, 2018.

By Sharon Gillson
 Sharon Gillson is a writer living with and covering GERD and other digestive issues.