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Generic name: bismuth subsalicylateBIZ-muth-sub-sa-LISS-i-late ]
Brand names: Bismarex, Bismatrol, Bismatrol Maximum Strength, Kaopectate, Kola-Pectin DS, ... show all 10 brands
Drug class: Antidiarrheals

Medically reviewed by Melisa Puckey, BPharm. Last updated on Oct 1, 2023.

What is Pepto-Bismol?

Pepto-Bismol is used to treat diarrhea, travelers' diarrhea, nausea, heartburn, indigestion, gas, or upset stomach.

Pepto-Bismol works as an antacid to reduce excess stomach acid and so eases discomfort. It also works to protect the stomach and lower part of your food pipe (esophagus) from stomach acid.

Pepto-Bismol can be taken as a tablet or liquid, depending on which one you prefer.


You should not use Pepto-Bismol if you have bleeding problems, blood in your stools, or if you are allergic to aspirin or other salicylates.

You should not use Pepto-Bismol for a stomach ulcer unless your ulcer is caused by H. pylori and your doctor has prescribed Pepto-Bismol as part of modified bismuth-containing quadruple therapy (mBCQT).

Using this medicine in a child or teenager with flu symptoms or chickenpox can cause a serious or fatal condition called Reye's syndrome.

Before taking this medicine

You should not use Pepto-Bismol if you are allergic to bismuth subsalicylate, or if you have:

Using this medicine in a child or teenager with flu symptoms or chickenpox can cause a serious or fatal condition called Reye's syndrome.

Ask a doctor or pharmacist if this medicine is safe to use if you have or have ever had:

Ask a doctor before using this medicine if you are pregnant or breastfeeding.

Do not give this medicine to a child younger than 12 years old without medical advice.

Pepto-Bismol may contain phenylalanine and could be harmful if you have phenylketonuria (PKU).

How should I take Pepto-Bismol?

Take this medicine exactly as directed on the label, or as prescribed by your doctor.

Shake the oral suspension (liquid) before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

You must chew the chewable tablet before you swallow it.

Drink plenty of liquids while you are taking this medicine.

Taking more than the recommended dose will not make this medicine more effective, and may cause serious side effects.

Call your doctor if you still have diarrhea after 2 days of using this medicine.

This medicine can affect the results of certain medical tests. Tell any doctor who treats you that you are using bismuth subsalicylate.

Store at room temperature away from moisture and heat. Do not freeze.

What happens if I miss a dose?

Since bismuth subsalicylate is used when needed. If you are on a dosing schedule, skip any missed dose. Do not use two doses at one time.

Do not take more than 8 doses per day.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include weakness, depression, anxiety, feeling irritable, problems with balance or coordination, confusion, tremors, or jerky muscle movements.

What should I avoid while taking Pepto-Bismol?

Ask a doctor or pharmacist before taking other antacids, diarrhea medicine, or taking medicine that may contain a salicylate (such as aspirin, salsalate, magnesium salicylate, choline salicylate, diflunisal, Ecotrin, Tricosal, Trilisate, and others).

Pepto-Bismol side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop taking this medicine and call your doctor at once if you have:

Bismuth subsalicylate may cause you to have a black or darkened tongue. This is a harmless side effect.

Common Pepto-Bismol side effects include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Pepto-Bismol?

Ask a doctor or pharmacist before using bismuth subsalicylate with any other medications, especially:

This list is not complete. Other drugs may affect Pepto-Bismol, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Popular FAQ

Several formulations of Pepto-Bismol can be used in children. The original strength of Pepto-Bismol liquid (“the pink stuff” or “Pepto”) can be given to children 12 years and older. Kids from 2 to 12 years can take Pepto Kids, a chewable, bubblegum-flavored tablet that contains the antacid calcium carbonate. Continue reading

Pepto-Bismol is an over-the-counter medication that usually works within 30 to 60 minutes. It can be used to treat diarrhea and upset stomach in people 12 years and older. Continue reading

Bismuth found in the active ingredient in Pepto-Bismol interacts with sulfur found naturally in your mouth and digestive tract to create bismuth sulfide, a substance that may turn your tongue black. It’s a harmless side effect and usually clears up a few days after you stop treatment. Continue reading

Pepto-Bismol is an over-the-counter (OTC) medicine that can be used to treat diarrhea and traveler's diarrhea in adults and children 12 years and older. For diarrhea, it’s available as an oral liquid, liquicap, or caplet. It typically takes 30 to 60 minutes to start working, but you may need several doses. Continue reading

Black hairy tongue is often caused by an overgrowth of papillae (taste buds) on the tongue. It results in a dark, furry appearance of dead skin cells on the surface of the tongue that can be stained from bacteria, food, or tobacco. Although it may be unpleasant, it doesn't usually require medical treatment and it's temporary and harmless. Continue reading

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Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.