Bismuth subsalicylate (Pepto-Bismol)

Pronunciation: BIZ-muth sub-sa-LIS-i-late.

Generic name
bismuth subsalicylate
Drug class
Salicylate; antidiarrhoeal and upset-stomach reliever (bismuth compound)
Form
Chewable tablet (262 mg); oral suspension/liquid (17.5 mg/ml, equivalent to 525 mg per 30 ml dose); caplet
Route
Oral
Legal status
Over-the-counter (OTC); Pharmacy medicine (P) in the UK

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada

Australia: · Full directory

What bismuth subsalicylate is and how it works

Pepto-Bismol is an over-the-counter medicine containing bismuth subsalicylate, used to relieve upset stomach, indigestion, heartburn, nausea, and diarrhoea (including travellers' diarrhoea). (1) (2)

Pepto-Bismol is taken by mouth as a chewable tablet, caplet, or liquid and is meant for short-term use (no more than 2 days) unless a doctor advises otherwise. Because it contains a salicylate (the same family of ingredient as aspirin), it carries the same Reye's syndrome caution in children and teenagers with a viral illness. It also commonly and harmlessly turns the stool and/or tongue dark or black -- a well-known, expected effect that can look alarming but is not a sign of a problem on its own.

Mechanism of action: how bismuth subsalicylate works

Bismuth subsalicylate forms a protective, mucosa-coating layer in the stomach and intestine and has mild antibacterial and anti-secretory actions relevant to travellers' diarrhoea; systemic absorption of the bismuth moiety is minimal, but the salicylate moiety is absorbed and shares the pharmacology (and Reye's-syndrome-related caution) of other salicylates such as aspirin. (1)

What bismuth subsalicylate is used for

Upset stomach and indigestion

Relieves symptoms of upset stomach, indigestion, heartburn, nausea, gas, belching, and fullness, often due to overindulgence in food or drink. (1) (2)

Diarrhoea, including travellers' diarrhoea

Controls diarrhoea and relieves the symptoms of travellers' diarrhoea. (1) (2)

Before taking bismuth subsalicylate

Do not take / not appropriate for

  • Do not give to children or teenagers who have or are recovering from chickenpox or flu-like (viral) illness symptoms, because of the risk of Reye's syndrome -- the same caution that applies to aspirin and other salicylates. (all countries) (1) (2)
  • Do not use if you are allergic to salicylates (including aspirin) or to any ingredient in the product. (all countries) (1) (2)
  • Do not use if you are taking other salicylate-containing products, including aspirin. (all countries) (1) (2)
  • Do not use if you have an ulcer, a bleeding problem, or bloody or black stool that is not the known, harmless darkening caused by this product itself. (United States) (1)
  • Do not use if you are under 16 years of age. (United Kingdom) (2)
  • Do not use if you are pregnant or breast-feeding. (United Kingdom) (2)

Tell your clinician about

  • Whether you are taking medicines for thinning the blood (anticoagulants), diabetes, gout, or (in some markets) tetracycline antibiotics -- bismuth subsalicylate can interact with these.
  • Any history of stomach ulcers, bleeding problems, or blood clotting disorders.
  • Whether you have a fever or mucus in the stool alongside your symptoms.
  • Pregnancy, plans for pregnancy, or breastfeeding.
  • Any known salicylate or aspirin allergy.
(1) (2)

How to take bismuth subsalicylate

  • Take by mouth, following the package directions for your specific product (tablet, caplet, or liquid).
  • Shake liquid products well before use.
  • Do not use for more than 2 days in a row unless a doctor tells you to.
  • Do not exceed the maximum stated dose in 24 hours -- using more than directed, or for longer than directed, has been associated with an increase in side effects.
(1) (2)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (4) (3) (5) (6)

Missed dose

This product is used as needed for symptoms rather than on a fixed schedule, so there is no missed-dose rule -- just follow the label directions for your next dose and do not exceed the maximum daily amount.

Overdose

Seek medical attention or contact a poison control centre if too much has been taken, especially in a child, or if signs of salicylate toxicity (such as ringing in the ears, rapid breathing, confusion, or severe nausea/vomiting) occur. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Temporary, harmless darkening (black or dark grey colour) of the stool and/or tongue -- an expected effect of the bismuth component, not a sign of bleeding. This can look alarming but typically resolves after stopping the product.

What to notice: Temporary, harmless darkening (black or dark grey colour) of the stool and/or tongue -- an expected effect of the bismuth component, not a sign of bleeding. This can look alarming but typically resolves after stopping the product.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1) (2)

Constipation.

What to notice: Constipation.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Reye's syndrome (children and teenagers with a viral illness) — high caution

Symptoms: Behaviour changes, confusion, unusual sleepiness, or persistent vomiting in a child or teenager who has or is recovering from chickenpox, flu, or another viral illness.

Action: Do not give this product to a child or teenager with chickenpox or flu-like symptoms without first checking with a doctor or pharmacist. If these symptoms occur after use, seek medical attention promptly -- this can be an early sign of Reye's syndrome, a rare but serious and potentially fatal illness. This is the same salicylate-related caution used for aspirin. (1) (2)

Genuine gastrointestinal bleeding (as distinct from the known harmless stool darkening) — emergency

Symptoms: Red or clearly bloody stool, vomiting blood or material that looks like coffee grounds, or severe abdominal pain -- these are different from the expected, harmless grey-black stool colour change this product commonly causes.

Action: If you are unsure whether stool changes are the expected bismuth effect or a genuine sign of bleeding, seek medical attention promptly for an assessment. (1)

Ringing in the ears or hearing changes — high caution

Symptoms: New ringing in the ears (tinnitus) or loss of hearing.

Action: If this occurs, see a doctor promptly -- this can be a sign of salicylate effect that needs medical assessment before continuing. (1) (2)

Symptoms that persist or worsen — high caution

Symptoms: Diarrhoea lasting more than 2 days, diarrhoea with fever, or symptoms that do not improve or get worse.

Action: If this occurs, see a doctor -- prolonged diarrhoea, especially with fever, needs medical assessment (and attention to staying hydrated, especially in frail or elderly people). (1) (2)

Interactions

  • Medicines for thinning the blood (anticoagulants) -- check with a doctor or pharmacist before use, because of the salicylate content. (1) (2)
  • Diabetes medicines -- check with a doctor or pharmacist before use. (1) (2)
  • Gout medicines -- check with a doctor or pharmacist before use. (1) (2)
  • Tetracycline antibiotics -- bismuth can reduce absorption of tetracyclines; check with a doctor or pharmacist before combining. (2)
  • Other salicylate-containing products, including aspirin -- avoid combining, because of additive salicylate effects. (1) (2)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

The UK label states this product should not be used during pregnancy. The US OTC label reviewed for this dossier does not carry an explicit pregnancy contraindication but the salicylate content means pregnant people should check with a doctor or pharmacist before use -- discuss with your prescriber or pharmacist. (1) (2) (4) (3) (5) (6)

Breastfeeding

The UK label states this product should not be used while breast-feeding. Discuss with your doctor or pharmacist if you are breastfeeding. (1) (2) (4) (3) (5) (6)

Children

Not to be given to children or teenagers with a current or recent viral illness (chickenpox, flu) because of the Reye's syndrome risk. The UK label additionally restricts use to those 16 years and over; other markets set the age cut-off differently by product label -- always follow the specific product's label directions. (1) (2) (4) (3) (5) (6)

Elderly

No specific dose adjustment is described based on age alone, but elderly or frail people with diarrhoea should pay particular attention to preventing dehydration (adequate fluids or oral rehydration products). (1) (2) (4) (3) (5) (6)

Hepatic_impairment

Not specifically addressed in the sources reviewed for this dossier; discuss with a doctor or pharmacist if you have liver disease. (1) (2) (4) (3) (5) (6)

Renal_impairment

Not specifically addressed in the sources reviewed for this dossier; discuss with a doctor or pharmacist if you have kidney disease, since bismuth and salicylate clearance may be affected. (1) (2) (4) (3) (5) (6)

Monitoring

Before starting

  • Confirm the person is not a child/teenager with a current or recent viral illness
  • Confirm no salicylate allergy and no other salicylate-containing products are being used
  • Check for any anticoagulant, diabetes, gout, or tetracycline antibiotic use

During treatment

  • Watch for behaviour changes, confusion, or persistent vomiting in children/teenagers, which could signal Reye's syndrome.
  • Distinguish the expected, harmless dark stool/tongue colour change from genuine signs of gastrointestinal bleeding.
  • If ringing in the ears, hearing changes, or symptoms lasting more than 2 days occur, seek care promptly.
(1) (2)

Storage

Store at room temperature away from excessive heat and moisture, as directed on the product packaging. Do not refrigerate or freeze the liquid suspension. Keep out of reach of children.

Professional information

Clinician-facing context only, sourced from the current US FDA OTC Drug Facts label and the UK MHRA-approved product label; verify against the current full label in the relevant jurisdiction before advising patients.

United States

Indication: Upset stomach, indigestion, heartburn, nausea, diarrhoea (including travellers' diarrhoea)

Dose summary: Adults and children 12+: 2 tablets (or liquid equivalent) every 30 minutes as needed, maximum 8 doses/24 hours, maximum 2 days of use.

Renal context: Not specifically addressed in the source reviewed for this dossier. (1)

United Kingdom

Indication: Heartburn, indigestion, nausea, upset stomach (overindulgence), diarrhoea

Dose summary: Adults and adolescents 16+: 30 ml oral suspension every 30-60 minutes as needed, maximum 8 doses/24 hours, maximum 2 days of use. Contraindicated under 16, in pregnancy, and while breast-feeding.

Renal context: Not specifically addressed in the source reviewed for this dossier. (2)

Mechanism of action

Hepatic guidance

Not specifically addressed in the sources reviewed for this dossier.

Overdose note

Overdose can produce salicylate-toxicity features (tinnitus, hyperventilation, confusion); bismuth itself is poorly absorbed and rarely the dominant toxicity concern at OTC doses, but repeated excessive or prolonged use should be avoided. (1)

Frequently asked questions

Why does Pepto-Bismol turn my stool or tongue black?

This is a well-known, harmless effect of the bismuth in the product reacting with trace amounts of sulfur in your saliva and digestive tract. It is not a sign of bleeding on its own and usually goes away once you stop taking the product. If you are ever unsure whether stool changes are this expected effect or something else (such as red or clearly bloody stool), check with a doctor or pharmacist. (1) (2)

Why shouldn't children or teenagers with chickenpox or flu take Pepto-Bismol?

Pepto-Bismol contains a salicylate (related to aspirin). Salicylates have been linked to Reye's syndrome, a rare but serious illness, when used in children or teenagers recovering from a viral illness such as chickenpox or flu. This is the same caution that applies to aspirin. (1) (2)

Is Pepto-Bismol available everywhere?

No. It is a long-established over-the-counter product in the US, UK, and Canada, confirmed directly with regulators in each of those markets. Its availability in the European Union, Australia, and New Zealand could not be confirmed during this research -- no marketing authorisation or consent-to-market record was found for those markets, so its status there should be treated as unresolved rather than assumed. (1) (2) (4) (3) (5) (6)

What is the mechanism of action of bismuth subsalicylate?

Bismuth subsalicylate forms a protective, mucosa-coating layer in the stomach and intestine and has mild antibacterial and anti-secretory actions relevant to travellers' diarrhoea; systemic absorption of the bismuth moiety is minimal, but the salicylate moiety is absorbed and shares the pharmacology (and Reye's-syndrome-related caution) of other salicylates such as aspirin. (1)

What is the generic name of Bismuth subsalicylate (Pepto-Bismol)?

The generic name is bismuth subsalicylate. (1)

What class of drug is bismuth subsalicylate?

Bismuth subsalicylate (Pepto-Bismol) is classed as: Salicylate; antidiarrhoeal and upset-stomach reliever (bismuth compound). (1)

References

  1. PEPTO BISMOL (bismuth subsalicylate) chewable tablet / suspension -- Drug Facts labelU.S. Food and Drug Administration / DailyMed (NIH), OTC Drug Facts label, The Procter & Gamble Manufacturing Company · United States · accessed 2026-07-30 · source 1
  2. Pepto-Bismol 17.5 mg/ml Oral Suspension -- approved UK product label, PL 00129/0358UK Medicines and Healthcare products Regulatory Agency (MHRA) approved product label, Procter & Gamble (Health & Beauty Care) Ltd. · United Kingdom · accessed 2026-07-30 · source 2
  3. Bismuth subsalicylate / Pepto-Bismol -- EU member-state availability research (no confirmed marketing authorisation found)Cross-checked secondary regulatory-context sources (consistent independent reporting on France's national restriction of bismuth-containing products); no primary EU member-state marketing authorisation for Pepto-Bismol/bismuth subsalicylate could be located via direct regulator search during this research · European Union · accessed 2026-07-30 · source 3
  4. Pepto Bismol Caplet 262 mg -- Health Canada Drug Product Database entry, DIN 02177994Health Canada Drug Product Database (DPD), Procter & Gamble Inc. · Canada · accessed 2026-07-30 · source 4
  5. Bismuth subsalicylate / Pepto-Bismol -- no ARTG registration foundTherapeutic Goods Administration (TGA) ARTG search (no registration found); cross-checked consistent secondary consumer/pharmacy sources · Australia · accessed 2026-07-30 · source 5
  6. Bismuth subsalicylate / Pepto-Bismol -- no Medsafe data sheet or consent-to-market record foundMedsafe (New Zealand regulator) product/application search -- no confirmed record found · New Zealand · accessed 2026-07-30 · source 6

Brand names by country

Single-ingredient bismuth subsalicylate names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Stomach relief262 mg, 525 mg/30mL, 525 mg5mL, 1050 mg/30mL · chain drug marketing association, inc.
  • Pepto Bismol262 mg, 525 mg/21, 525 mg5mL, 525 mg, 525 mg/30mL · procter & gamble manufactura s de rl de cv
  • Pink Bismuth262 mg, 525 mg/30mL, 262 mg5mL · discount drug mart, inc
  • TopCare Stomach Relief Ultra Strength262 mg, 525 mg5mL, 525 mg/30mL · topco associates, llc
  • Digestive Relief525 mg/30mL, 262 mg · target corporation
  • HEB Stomach Relief525 mg/30mL, 262 mg, 1050 mg/30mL · h e b
  • Upset Stomach Relief-Bismuth Subsalicylate 262 mg262 mg · pioneer life sciences, llc
  • Ultra Strength digestive relief525 mg · the kroger co.
  • Goodsense Regular strength Stomach Relief 122262 mg · good sense (geiss, destin & dunn, inc.)
  • CVS Stomach Relief525 mg5mL, 262 mg · cvs pharmacy

United Kingdom

  • Pepto-Bismol (2)MHRA licensed PL 00129/0358 confirmed · 17.5 mg/ml oral suspension (525 mg/30 ml dose) · Procter & Gamble (Health & Beauty Care) Ltd.

Canada

  • PEPTO-BISMOL
  • BISMUTH CHEWABLES
  • PEPTO-BISMOL WITH INSTACOOL
View brands in additional countries.

This page provides general reference information about Pepto-Bismol (bismuth subsalicylate) and is not a substitute for advice from a doctor or pharmacist. Follow the product label directions, and seek medical advice for use beyond 2 days, in children or teenagers with a viral illness, or if you are pregnant or breastfeeding.

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