We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission. Here’s our process.


Chances are you’ve heard of “the pink stuff.” Pepto-Bismol is a well-known over-the-counter medication used to treat digestive problems. If you’re feeling a bit queasy, read on to learn what to expect when taking Pepto-Bismol and how to use it safely.

Pepto-Bismol is used to treat diarrhea and relieve the symptoms of an upset stomach. These symptoms can include heartburn, nausea, and indigestion. They can also include gas, belching, and a feeling of fullness. The active ingredient in Pepto-Bismol is called bismuth subsalicylate. It belongs to the drug class called salicylates. Pepto-Bismol is available in regular strength as a caplet, chewable tablet, and liquid. It’s available in maximum strength as a liquid. All forms are taken by mouth.

Pepto-Bismol is thought to treat diarrhea by:

  • increasing the amount of fluid your intestines absorb
  • reducing inflammation and overactivity of your intestines
  • preventing your body’s release of a chemical called prostaglandin that causes inflammation
  • blocking toxins produced by bacteria such as E. coli
  • killing other bacteria that cause diarrhea

The active ingredient, bismuth subsalicylate, also has antacid properties that can help to decrease heartburn, upset stomach, and nausea.

Adults and children 12 years and older can take any of the following forms of Pepto-Bismol for up to two days. The dosages below apply for all digestive problems Pepto-Bismol can help treat. If your condition lasts longer than two days or if you have ringing in your ears, stop taking Pepto-Bismol and call your doctor.

Liquid suspension

Regular strength:

  • Take 30 mL (525 mg) every 30–60 minutes as needed.
  • Do not take more than eight doses (240 mL) in 24 hours.

Maximum strength:

  • Take 30 mL (1,050 mg) every 60 minutes as needed.
  • Do not take more than four doses (120 mL) in 24 hours.

Chewable tablets

  • Take two tablets (262 mg each) every 30–60 minutes as needed.
  • Chew or dissolve the tablets in your mouth.
  • Do not take more than eight doses (16 tablets, or 4,192 mg) in 24 hours.


  • Take two caplets (262 mg each) every 30–60 minutes as needed.
  • Swallow the caplets whole with water. Do not chew them.
  • Do not take more than eight doses (16 caplets or 4,192 mg) in 24 hours.

Most side effects from Pepto-Bismol are mild and go away shortly after you stop taking the medication.

More common side effects

The more common side effects of Pepto-Bismol include:

  • black stool
  • black, hairy tongue

These side effects are harmless. Both effects are temporary and go away within several days after you stop taking Pepto-Bismol.


Why can Pepto-Bismol give me black stool and a black, hairy tongue?

Anonymous patient


Pepto-Bismol contains a substance called bismuth. When this substance mixes with sulfur (a mineral in your body), it forms another substance called bismuth sulfide. This substance is black. When it forms in your digestive tract, it mixes with food as you digest it. This makes your stool turn black. When bismuth sulfide forms in your saliva, it turns your tongue black. It also causes a buildup of dead skin cells on your tongue’s surface, which can make your tongue look furry.

Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Serious side effect

Ringing in your ears is an uncommon and serious side effect of Pepto-Bismol. If you have this side effect, stop taking Pepto-Bismol and call your doctor right away.

Pepto-Bismol may interact with any other medications you may be taking. Talk to your pharmacist or doctor to see if Pepto-Bismol interacts with any medications you take.

Examples of medications that can interact with Pepto-Bismol include:

  • Angiotensin-converting enzyme (ACE) inhibitors such as benazepril, captopril, enalapril, fosinopril, lisinopril, and trandolapril
  • Blood thinners (anticoagulants) such as warfarin
  • Medications for diabetes such as insulin, metformin, sulfonylureas, dipeptidyl-peptidase-IV (DPP-IV) inhibitors, and sodium glucose transporter (SGLT) 2 inhibitors
  • Medications for gout such as probenecid
  • Methotrexate
  • Other salicylates such as aspirin
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin, naproxen, ibuprofen, meloxicam, indomethacin, and diclofenac
  • Phenytoin
  • Tetracycline antibiotics such as demeclocycline, doxycycline, minocycline, and tetracycline
  • Anti-seizure drugs such as valproic acid and divalproex

Pepto-Bismol is typically safe for most people, but you should avoid it if you have certain health conditions. Pepto-Bismol may make them worse. You should not take Pepto-Bismol if you:

  • are allergic to salicylates (including aspirin or NSAIDs such as ibuprofen, naproxen, and celecoxib)
  • have an active, bleeding ulcer
  • are passing bloody stools or black stools that are not caused by Pepto-Bismol
  • are a teenager who has or is recovering from chicken pox or flu-like symptoms

Bismuth subsalicylate may also cause problems for people with other medical conditions. Before taking Pepto-Bismol, tell your doctor if you have any of the following medical conditions. They can tell you if it’s safe to use Pepto-Bismol. These conditions include:

  • stomach ulcers
  • bleeding problems such as hemophilia and von Willebrand disease
  • kidney problems
  • gout
  • diabetes

Stop taking Pepto-Bismol and call your doctor right away if you have vomiting and extreme diarrhea along with behavior changes such as loss of energy, aggressive behavior, or confusion. These symptoms could be early signs of Reye’s syndrome. This is a rare but serious illness that can affect your brain and liver.

Keep reading: Reye’s syndrome causes, symptoms, and diagnosis »

You should not use Pepto-Bismol to self-treat diarrhea if you have a fever or stools that contain blood or mucus. If you have these symptoms, call your doctor right away. They could be signs of a serious health condition, such as an infection.

In case of overdose

Symptoms of an overdose of Pepto-Bismol can include:

  • ringing in your ears
  • loss of hearing
  • extreme drowsiness
  • nervousness
  • fast breathing
  • confusion
  • seizures

If you think you’ve taken too much of this drug, call your doctor or local poison control center. If your symptoms are severe, call 9-1-1 or go to the nearest emergency room right away.

For many people, Pepto-Bismol is a safe, easy way to relieve common stomach problems. But if you have any concerns about whether Pepto-Bismol is a safe option for you, be sure to ask your doctor or pharmacist. You should also call your doctor if Pepto-Bismol doesn’t ease your symptoms after two days.

Shop for Pepto-Bismol.