Pepto-Bismol vs. Tums: Which works better?

If you deal with occasional heartburn, indigestion, or an upset stomach, you’ve likely seen Pepto-Bismol (the pink liquid) and Tums (the chewable tablets) at your local pharmacy or supermarket. Both are over-the-counter (OTC) options, but they work differently and are best for different symptoms.

RELATED: What’s the best heartburn medicine for you?

Pepto-Bismol vs. Tums: Quick comparison chart
Feature	Pepto-Bismol	Tums
Active ingredient	Bismuth subsalicylate	Calcium carbonate
Drug class	Antacid + antidiarrheal	Antacid
Forms	Liquid, tablets, chewables	Chewable tablets
Works for heartburn?	Yes	Yes
Works for diarrhea?	Yes	No
Works for H. pylori ulcers?	Yes (with antibiotics)	No
Typical adult dose	262-524 mg every 30 min as needed (max 4,200 mg/day)	1,000-3,000 mg as needed (max 7,500 mg/day)
Treatment length	No more than 2 days (unless using for H. pylori treatment)	No more than 14 days

How they work

Pepto-Bismol

Pepto-Bismol contains bismuth subsalicylate. It:

• Coats your stomach lining
• Reduces inflammation
• Fights certain bacteria/neutralizes bacterial toxins
• Decreases fluid loss in diarrhea

That’s why it helps with:

• Heartburn
• Upset stomach
• Nausea
• Diarrhea (including traveler’s diarrhea)

It’s also part of combination therapy to treat Helicobacter pylori infections, a common cause of stomach ulcers.

Tums

Tums contains calcium carbonate, which:

• Directly neutralizes stomach acid
• Works fast (often within five minutes)

Because it creates carbon dioxide when neutralizing acid, you may notice belching or gas.

Tums is best for:

• Occasional heartburn
• Indigestion
• Sour stomach

Tums is not meant to treat diarrhea; however, it may indirectly help diarrhea by slowing down stools due to its calcium component.

Efficacy

Both Pepto-Bismol and Tums are approved by the U.S. Food and Drug Administration to relieve heartburn, indigestion, and upset stomach. There are no major head-to-head clinical trials directly comparing Pepto vs. Tums. Choosing the best medication depends on your symptoms.

Which one works better?
Symptom	Better choice
Quick heartburn relief	Tums
Upset stomach with nausea	Pepto-Bismol
Diarrhea	Pepto-Bismol
Suspected ulcer from H.pylori	Pepto-Bismol (with antibiotics)

How long do they last?

• Tums: Works fast but lasts about 30-60 minutes.
• Pepto-Bismol: Slightly slower onset, but symptom relief can last a few hours.

If you have frequent heartburn (more than twice weekly), you may need a different medication like:

• H2 blockers (famotidine/Pepcid)
• Proton pump inhibitors (PPIs) like omeprazole (Prilosec)

Updated clinical guidance from the American College of Gastroenterology: For frequent GERD symptoms, PPIs are considered first-line therapy over antacids because they reduce acid production rather than just neutralizing it.

RELATED: See more GERD medications

Side effects of Pepto-Bismol vs. Tums
Side effect	Pepto-Bismol	Tums
Constipation	Common	Common
Black stool/tongue	Common and harmless	No
Dry mouth	No	Common
Tinnitus (ringing in ears)	Rare	No
Gas	No	Common
High calcium levels	No	Rare but possible

This may not be a complete list of adverse effects that can occur. Please refer to your doctor or healthcare provider to learn more.

Source: NIH (Pepto-Bismol), NIH (Tums) 

Important notes

• Black stool from Pepto is temporary and not dangerous.
• Tums overuse can cause hypercalcemia or milk-alkali syndrome, especially if you:
  • Take calcium supplements
  • Have kidney disease
  • Use high doses long-term

How to prevent constipation from Tums and Pepto-Bismol

Some natural remedies for constipation include drinking more water, slowly eating more fiber-rich foods, and exercising regularly. Taking these medications for a short period of time can also help prevent side effects.

Drug interactions

Both medications can interfere with certain medications. Avoid taking them close together with:

• Tetracycline antibiotics
• Quinolone antibiotics (like ciprofloxacin)
• Iron supplements
• Antifungals like itraconazole

These medications should be spaced at least two hours apart from the Pepto-Bismol and Tums.

Use extra caution with Pepto-Bismol because it’s related to aspirin, which can:

• Increase bleeding risk with warfarin
• Interact with gout medications
• Trigger salicylate sensitivity

Can you take Pepto-Bismol and Tums together?

Yes, generally you can. They work differently and do not have a known direct interaction. However, don’t exceed maximum doses and ask your pharmacist if you take other medications.

Can you take Imodium and Pepto-Bismol together?

You can take Imodium and Pepto together, but it’s not recommended since it can increase your risk of constipation.

Who should avoid these medications?

Avoid Pepto-Bismol if:

• You’re allergic to aspirin
• You’re taking blood thinners
• Your child is younger than 12 years old, especially those recovering from the flu or chickenpox (due to the risk of Reye’s syndrome)
• You’re pregnant (generally not recommended)

Note: Some versions labeled “Children’s Pepto” contain calcium carbonate (the active ingredient in Tums), not bismuth. Always check the label.

”What’s ironic is that ‘Kids Pepto’ is nothing more than Tums (calcium carbonate), as the real Pepto-Bismol should be used with caution in children with viral symptoms, due to the rare but serious risk of Reye’s syndrome,” says Jesse Houghton, MD, FACG, senior medical director of Gastroenterology at Southern Ohio Medical Center.

Use caution with Tums if:

• You have kidney disease
• You take calcium supplements
• You’re prone to kidney stones

Pregnant women often use Tums occasionally for heartburn, but check with your provider first if you’re experiencing heartburn or indigestion while pregnant.

RELATED: Home remedies for heartburn

Cost and savings

These medications are generally affordable over-the-counter options.

Average prices:

• Pepto-BIsmol: $10-$15
• Tums: $5-$12

Insurance, Medicare, and Medicaid usually do not cover OTC products unless prescribed.

Money-saving tips:

• Store brands and generics often contain the same active ingredient for less.
• Ask your healthcare provider for a prescription and use SingleCare to save up to 80% without insurance.
• If you need long-term treatment, ask your doctor about prescription-strength options that may be covered by insurance.

RELATED: Get the SingleCare discount card

Frequently asked questions

Does Pepto-Bismol help with acid reflux?

Pepto can help with acid reflux by coating the stomach and esophagus, but it does not treat the root cause of acid reflux. 

Can Tums help with gas?

There is a specific form of Tums with simethicone that can relieve gas, but the standard product of Tums does not, and can even cause gas as a side effect.

Can I use Pepto-Bismol or Tums with alcohol?

Alcohol in moderation may be safe while taking Pepto-Bismol or Tums. However, excessive or chronic alcohol use may irritate the lining of the stomach or intestines, which may worsen the stomach problems that Pepto-Bismol and Tums are designed to relieve. For this reason, you may want to avoid drinking alcohol while taking Pepto-Bismol or Tums.

How long does it take for them to work?

Tums start working within five minutes and can be taken as needed. Pepto-Bismol starts working within 30-60 minutes. Do not exceed more than eight doses in 24 hours.

Is Pepto Bismol an antacid?

Pepto-Bismol has mild antacid effects that help relieve uncomfortable symptoms of heartburn and indigestion. It also acts as an antidiarrheal agent, commonly used to treat traveler’s diarrhea. Pepto-Bismol works by coating the lining of the digestive tract while preventing fluid and electrolyte loss. It also has antibacterial properties.

How long can I take them?

Use Pepto-Bismol for no more than two days, unless instructed otherwise by your provider. Tums should be taken for no more than 14 days.

If you feel the need to use them consistently, consult a healthcare provider, as persistent heartburn may be a sign of a more serious underlying condition. 

Expert takeaway

“Tums and Pepto-Bismol are both commonly recommended over-the-counter medications for mild heartburn and stomach upset, with Pepto-Bismol having the added benefit of helping with nausea and diarrhea. I always warn my patients that taking Pepto-Bismol can make the stool black, which is often confused with an upper GI bleed. This is nothing to be concerned about,” says Jesse Houghton, MD, FACG, a member of the SingleCare Medical Review Board.