The standard adult dose of Pepto-Bismol is 30 mL (2 tablespoons) of regular-strength liquid or 2 chewable tablets, taken every 30 minutes to 1 hour as needed. You can take up to 8 doses in 24 hours, and you shouldn’t use it for more than 2 days in a row without talking to a doctor.
Adult Dosage by Product Type
Pepto-Bismol comes in several forms, and the dose differs slightly depending on which one you’re using. All dosing below applies to adults and children 12 and older.
Regular-strength liquid: Take 2 tablespoons (30 mL) every 30 minutes to 1 hour as needed. Do not exceed 16 tablespoons (8 doses) in 24 hours.
Ultra-strength liquid: Take 15 mL (one dose cup) every 30 minutes, or 30 mL every hour. The maximum is 8 doses (120 mL) in 24 hours. Shake the bottle well and use the dose cup that comes with it.
Chewable tablets: Take 2 tablets every 30 minutes, or 4 tablets every hour. The maximum is 16 tablets (8 doses) in 24 hours.
For diarrhea specifically, use it until the diarrhea stops but not for more than 2 days. For general stomach upset, heartburn, indigestion, or nausea, the same dose applies but stick to 2 tablets every 30 minutes to 1 hour rather than the higher 4-tablet-per-hour option.
Dosage for Children
Children under 12 should not take regular Pepto-Bismol. The active ingredient, bismuth subsalicylate, is chemically related to aspirin. Giving aspirin-related products to children, especially those with a viral illness like the flu or chickenpox, raises the risk of Reye’s syndrome, a rare but serious condition that damages the brain and liver.
There is a separate product called Pepto Kids, which uses calcium carbonate instead of bismuth subsalicylate. The dosing is based on weight first, age second:
- 24 to 47 lbs (ages 2 to 5): 1 tablet, up to 3 tablets in 24 hours
- 48 to 95 lbs (ages 6 to 11): 2 tablets, up to 6 tablets in 24 hours
- Under 24 lbs or under age 2: Do not use without a doctor’s guidance
How Long You Can Safely Take It
Pepto-Bismol is meant for short-term use. If your symptoms get worse or last more than 2 days, stop taking it. The safety of using it beyond 3 weeks has not been established, even at lower doses. For something like traveler’s diarrhea prevention, where people sometimes take it daily while abroad, studies from Mexico showed it cuts the risk of getting sick roughly in half, but the CDC notes the dosing schedule is inconvenient and the product hasn’t been proven safe for use beyond that 3-week window.
Who Should Avoid Pepto-Bismol
Because Pepto-Bismol contains salicylates (the same family of compounds found in aspirin), it interacts with several types of medication. You should not take it if you’re using blood thinners, oral diabetes medications, or gout medications without checking with a pharmacist or doctor first. If you’re on tetracycline antibiotics like doxycycline or minocycline, leave at least a 2-hour gap before taking Pepto-Bismol, since it can interfere with absorption.
Don’t combine it with aspirin or ibuprofen on your own. The salicylate content stacks with aspirin, increasing the risk of side effects. People with an aspirin allergy or kidney problems should avoid it entirely.
Pepto-Bismol is not safe during pregnancy, particularly after 30 weeks, when it can affect the baby. It’s also not recommended while breastfeeding. If you need relief for stomach issues during pregnancy or nursing, a doctor or pharmacist can suggest alternatives that are safer for both you and your baby.
Common Side Effects to Expect
Pepto-Bismol commonly turns your tongue and stool black. This is harmless and temporary, caused by bismuth reacting with trace amounts of sulfur in your saliva and digestive tract. It goes away once you stop taking the product. If you see black stool and haven’t been taking Pepto-Bismol, that’s a different situation worth getting checked out, since it can indicate bleeding in the digestive tract.