Why does Pepto-Bismol turn your tongue black?
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.
The active ingredient in Pepto-Bismol is bismuth subsalicylate. The interaction between bismuth and sulfur can also cause your stools (poop) to look darker or black, which is also a temporary and harmless side effect
If your black tongue does not go away in a few days, or you notice a black tongue or darkened stools but you have not used Pepto-Bismol, contact your doctor for evaluation. Dark stools or a black tongue can also be caused by certain medical conditions or other drugs.
How do you get rid of black tongue from Pepto-Bismol?
A few days after you stop using Pepto-Bismol, your tongue discoloration should go away on its own, so you don’t really need to do anything. Pepto-Bismol is usually out of your system in one day, but it can take several days for the side effect to go away.
Does Pepto-Bismol cause black hairy tongue?
A "pseudo-black hairy tongue" (that mimics the look of black hairy tongue without the elongated cells on the tongue) can occur from using products containing bismuth like Pepto-Bismol. Other products that can cause "pseudo-black hairy tongue" include certain foods, tobacco and medicines like antibiotics or antidepressants.
You should continue to practice good oral hygiene by brushing twice a day and flossing. Gently brushing your tongue with a soft bristle toothbrush may help to remove any discolored or dead cells on your tongue, although you should not have any elongated tongue cells with Pepto-Bismol use.
Related: What causes black hairy tongue?
What does Pepto-Bismol treat and how does it work?
Pepto Bismol is an over-the-counter (OTC) medicine used to treat diarrhea, travelers' diarrhea, nausea, heartburn, indigestion, gas, or upset stomach.
It’s available OTC as a liquid, tablet, capsule, chewable forms, and gummies and can be found at most retail shops and pharmacies in the U.S. Read the Drug Facts Labels found on over-the-counter products in the U.S. for for directions and safety warnings.
Pepto-Bismol works by preventing secretions in your intestinal tract, increasing fluid reabsorption, and decreasing inflammation and bacteria growth that may contribute to diarrhea.
Related questions
- Can you give Pepto Bismol to kids?
- What is the fastest way to stop diarrhea?
- How long does it take for Pepto Bismol to work?
What is the main ingredient in Pepto-Bismol?
The active ingredient in Pepto Bismol is bismuth subsalicylate, a compound that is chemically related to aspirin and contains similar warnings. Pepto-Bismol is indicated for use in adults and children 12 years and over. Always follow the label directions and Drug Facts found on the package.
Children, adolescents and even older teenagers who have or are recovering from chicken pox, flu or flu-like symptoms should not use Pepto-Bismol due to the possible risk of Reye syndrome.
- Reye syndrome is a very a serious illness that may rarely occur in children who have used salicylates. It may lead to permanent brain damage or death in children. It requires immediate medical treatment.
- Changes in behavior, extreme tiredness, confusion, nausea or vomiting or seizures may be signs of Reye syndrome.
- Contact your doctor right away or call 911 right away if your child has taken Pepto-Bismol and you notice these symptoms.
You should not use bismuth subsalicylate (Pepto-Bismol) if you have bleeding problems, a stomach ulcer, blood in your stools, or if you are allergic to aspirin or other salicylates.
This is not all the information you need to know about Pepto-Bismol and does not take the place of your doctor’s directions. Discuss any medical questions you have with your doctor or other health care provider.
References
- Budisak P, Abbas M. Bismuth Subsalicylate. [Updated 2023 Jun 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.
- Gurvits GE, Tan A. Black hairy tongue syndrome. World J Gastroenterol. 2014 Aug 21;20(31):10845-50. doi: 10.3748/wjg.v20.i31.10845. PMID: 25152586; PMCID: PMC4138463.
- Pepto Bismol (bismuth subsalicylate) Drug facts label. The Proctor and Gamble Manufacturing Company. Accessed July 24, 2025.
- FAQs. Pepto-Bismol.com. Accessed July 24, 2025.
Read next
Does Pepto-Bismol help with diarrhea?
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
What causes black hairy tongue?
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
Can you take an antacid with omeprazole?
You can take an antacid with omeprazole if you are still getting symptoms of indigestion because it can take several days for omeprazole to start working. Take omeprazole as directed (usually taken once daily on an empty stomach), and take antacids as needed to relieve indigestion pain after eating. But tell your doctor if several weeks have gone past and omeprazole does not seem to be working or you are still taking antacids. Continue reading
See also:
Related medical questions
- Pepto-Bismol - How long will your stool be dark for?
- My stool has changed color. What does it mean?
- How to stop diarrhea - any medicine or remedy suggestions?
- Is using expired Pepto-Bismol a hazard or health risk?
- Over the Counter Medication for Pets
- What are 7 Essential First Aid Kit Items?
- Heartburn vs Acid Reflux vs GERD - What is the difference?
- What foods should I avoid when taking omeprazole?
- Is famotidine safer than omeprazole for heartburn?
- Nexium vs Prilosec: What's the difference between them?
- Does omeprazole cause cancer?
- Can proton pump inhibitors (PPIs) be used long-term?
- The Do's and Don'ts of Treating Heartburn
- What medications and vaccines should I take for travel?
- Should you take probiotics with antibiotics?
- What to eat when you have a stomach virus?
- How long does the flu last for?
- Can antibiotics cause diarrhea?
- What type of diarrhea does Aemcolo (rifamycin) treat?
- Why does metformin cause diarrhea?
- How long does Imodium stop diarrhea for?
- Can you take metformin without food?
- Can Flagyl be used to treat diarrhea?
- What is berberine used for?
- Does Flagyl cause diarrhea?
- How often does diarrhea occur with Linzess?
- Does Adderall have a laxative or constipating effect?
- Why is my poop green? What does this mean?
- Why does Ofev cause diarrhea?
- If I am Lactose Intolerant or Lactose Allergic, are there Medications I should Avoid?
Drug information
- Pepto-Bismol Information for Consumers
- Side Effects of Pepto-Bismol (detailed)
- Pepto-Bismol user reviews (35)
Related support groups
- Pepto-Bismol (31 questions, 15 members)
- Indigestion (47 questions, 87 members)
- Diarrhea (218 questions, 395 members)
- Helicobacter Pylori Infection (27 questions, 209 members)
- Traveler's Diarrhea (9 questions, 5 members)