For most healthy adults, yes: neither the Tums label nor the Pepto-Bismol label lists the other as a drug to avoid, and neither gives a waiting time between them. They do different jobs. Tums (calcium carbonate) is an antacid for heartburn and acid indigestion, while Pepto-Bismol (bismuth subsalicylate) treats diarrhea and upset stomach and contains salicylate, the same family as aspirin. Stay under each product's own daily cap, stop Pepto after 2 days, and treat chest pain as a possible heart problem, not heartburn.
What does each one do?
Tums is calcium carbonate, an antacid. Its label covers heartburn, acid indigestion, sour stomach and the upset stomach that comes with them.
Pepto-Bismol is bismuth subsalicylate. Its label covers diarrhea, traveler's diarrhea and upset stomach from eating or drinking too much, including heartburn, indigestion, nausea, gas, belching and fullness. It contains salicylate, the same family as aspirin, which is where most of its warnings come from.
- Heartburn only: both labels list it, so you may not need both.
- Diarrhea or nausea: Tums is not labeled for these. Pepto is.
- Taking both: neither label warns against it. If you need 2 products to feel okay, that is worth a question to a pharmacist or clinician.
Do I need to space Tums and Pepto apart?
Neither label sets a gap between these 2 products. The Tums label says antacids may interact with certain prescription drugs, and to ask a doctor or pharmacist first if you take one. Pepto-Bismol is not a prescription drug.
MedlinePlus gives a broader rule for calcium carbonate: avoid taking it within 1 to 2 hours of other medicines, because calcium can make some of them work less well. No source we read says this applies to Pepto in particular. If you want the cautious option, take one, then wait 1 to 2 hours before the other.
Spacing matters more for your other medicines. MedlinePlus says calcium can make other medicines work less well, and some antibiotics need careful timing with antacids. See our page on Tums with antibiotics for the details.
How much of each can I take in a day?
These caps come from the current US labels on DailyMed for adults and children 12 and older. Check your own box, since strengths differ.
- Tums Regular Strength 500: no more than 15 tablets in 24 hours, or 10 if pregnant.
- Tums Extra Strength 750: no more than 10 tablets in 24 hours, or 6 if pregnant.
- Tums Ultra 1000: no more than 7 tablets in 24 hours, or 5 if pregnant.
- All Tums: do not use the maximum dose for more than 2 weeks unless a doctor tells you to.
- Pepto-Bismol Original liquid: 30 mL per dose, no more than 8 doses (240 mL) in 24 hours.
- Pepto-Bismol chewables: 2 tablets per dose, no more than 8 doses (16 tablets) in 24 hours.
- All Pepto-Bismol: use for no more than 2 days. Children under 12 should ask a doctor.
What about Pepto Ultra, Pepto chewables and Pepto Kids?
Pepto-Bismol Ultra liquid is about twice as strong as Original. It has 525 mg of bismuth subsalicylate in 15 mL, while Original has 525 mg in 30 mL. The dose cup amount is half, but the cap is still 8 doses, which for Ultra is 120 mL. Don't use the Original measuring amount with the Ultra bottle.
Pepto chewables have 262 mg of bismuth subsalicylate per tablet. They also list calcium carbonate as an inactive ingredient, with 50 mg of calcium per tablet. That is a small amount, but it is extra calcium on top of Tums.
Pepto Kids is a different drug. Its active ingredient is calcium carbonate, the same as Tums, at 400 mg per tablet. It is dosed by weight for ages 2 to 11, and the label says to ask a doctor for children under 2. Do not give a child Pepto Kids and Tums together, because that doubles up the same ingredient. Regular Pepto-Bismol is not labeled for children under 12 without a doctor's advice.
Who should skip Pepto or check first?
Most of Pepto's warnings come from its salicylate. Tums does not carry these warnings.
- Do not use Pepto if you are allergic to aspirin or other salicylates, or already take another salicylate product.
- Do not use Pepto if you have an ulcer, a bleeding problem, or bloody or black stool.
- Children and teens who have or are getting over chickenpox or flu-like symptoms should not use Pepto, because of the risk of Reye's syndrome.
- Ask a doctor first if you have a fever or mucus in your stool.
- Ask a doctor or pharmacist first if you take a blood thinner or a medicine for diabetes, gout or arthritis.
- Pregnant or breastfeeding: the Pepto label says to ask a health professional first. Tums has lower daily caps in pregnancy.
- Kidney disease: MedlinePlus says to tell your doctor before taking calcium carbonate.
When should you get care?
In an emergency, call 911Contact a clinician if your symptoms get worse or last more than 2 days on Pepto, if you need Tums for heartburn for more than 2 weeks, or if you have a fever or mucus in your stool.
Contact a clinician soon if belly pain does not improve in 24 to 48 hours, you have a fever over 100°F with belly pain, or you can't keep down food or liquids. Stop Pepto and call a doctor if you get ringing in your ears or hearing loss.
Get care the same day if your stool was black or tarry before you took Pepto, or if you feel faint or weak.
Call 911 for chest pain or pressure, especially if it spreads to your jaw, left arm or between your shoulder blades, or comes with sweating, nausea, dizziness or shortness of breath. Do not wait to see if an antacid helps.
Call 911 or get emergency care for vomiting blood, bright red or maroon blood in your stool, black tarry stool with belly pain that started before you took Pepto, sudden sharp belly pain, or a belly that is hard and rigid to the touch.
How our AI doctor decides when to send you to care ›Is a black tongue or black stool normal after Pepto?
Yes, Pepto can turn your tongue or stool dark. The label calls this temporary and harmless.
The tricky part: black, tarry stool can also be a sign of bleeding, and the Pepto label says not to use it if you already have bloody or black stool. If your stool was black or tarry before you took Pepto, or you feel faint or weak, get checked the same day. Vomiting blood is a reason to call 911. Ringing in your ears or hearing loss on Pepto means stop and call a doctor.
Common questions
Can I take Tums and Pepto-Bismol together?
For most healthy adults, yes. Neither label lists the other as a drug to avoid, and neither sets a gap between them. Stay under each product's daily cap and stop Pepto after 2 days. If you want to be cautious, MedlinePlus advises keeping calcium carbonate 1 to 2 hours away from other medicines.
Which is better for heartburn, Tums or Pepto?
Both labels list heartburn. Tums is a plain antacid and does not carry Pepto's salicylate warnings, such as aspirin allergy, ulcers, bleeding problems and Reye's syndrome in children and teens. Pepto also covers nausea and diarrhea, which Tums does not.
Can I take Tums after Pepto made my stomach feel worse?
If your symptoms got worse on Pepto, the label says to stop and ask a doctor. Adding Tums can ease acid, but worsening pain is a reason to get checked, not to stack more medicine.
Is Pepto Ultra stronger than regular Pepto?
Yes. Ultra has the same 525 mg of bismuth subsalicylate in half the liquid, 15 mL instead of 30 mL. Measure with the cup that comes with your bottle, and keep to 8 doses in 24 hours.
Can I give my child Tums and Pepto Kids?
No. Pepto Kids is calcium carbonate, the same active ingredient as Tums, so giving both doubles the dose. The Tums labels we checked give directions only for ages 12 and up, and regular Pepto-Bismol needs a doctor's advice under 12.
Pymander is not a replacement for a physician and does not provide medical advice, diagnosis, or treatment. Always seek the advice of a qualified health provider with questions about a medical condition. If you think you may have a medical emergency, call 911.