Compare Tagamet vs. Tums

Head-to-head comparisons of medication uses, side effects, ratings, and more.


(Calcium Carbonate)

Relieves heartburn and acid tummy. Tagamet (Cimetidine) works well for heartburn but may not last as long or start working as quickly as other antacids.Relieves heartburn. Tums (Calcium Carbonate) gives quick relief for heartburn, but don't expect it to last all day.
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Reviews & ratings
Filter group. All currently selected
Filter group. All currently selected
Reviews for Tagamet (Cimetidine)
of people say Tagamet (Cimetidine) is worth it
say it works well
say it's a big hassle
631 reviews
Reviews for Tums (Calcium Carbonate)
+19% vs. Tagamet (Cimetidine)
+7% vs. Tagamet (Cimetidine)
+7% vs. Tagamet (Cimetidine)
1370 reviews
Side effects
  • Headache 2%
More Tagamet side effects »

We haven’t found good data for Tums side effects.

FDA side effect reports for Tums »
How it works
Tagamet (Cimetidine) is a type of antacid called an H2 blocker. It blocks the chemical histamine, which lowers acid production in your stomach. This treats heartburn and helps ulcers heal.Tums (Calcium Carbonate) is an antacid. It counteracts the effects of stomach acid to relieve heartburn and acid tummy (indigestion).
Type of medication
Acid reducer
Histamine blocker
Prescription or OTC
Available as
  • Pill
  • Liquid
  • Chewable tablet
  • Liquid
Used for (click to learn more)
Risk factors for serious side effects
    • Current kidney disease
    • Current liver disease
    • Age 50 or older
    • Current severe illness
      • Autoimmune disease
      • HIV or AIDS
      • Organ transplant
      • People without a spleen
      Detailed Tagamet (Cimetidine) risks & warnings »
        • Current kidney disease
        • Kidney dialysis
        • Hyperparathyroid disease
        • Taking high doses of Vitamin D
        • Previous kidney stones
        Detailed Tums (Calcium Carbonate) risks & warnings »
        Pregnancy category
        BFDA pregnancy category (Probably safe)

        Research studies with animals haven’t found a risk to unborn babies, but it hasn’t been properly studied in humans.

        See the FDA package insert
        NFDA pregnancy category (Unknown)

        The FDA hasn’t classified this medicine’s effects on unborn babies. Talk with your doctor about this medicine if you’re pregnant or planning on it.

        See the FDA package insert
        No specific alcohol-related info.No specific alcohol-related info.
        No specific food-related info.No specific food-related info.
        Kidneys and liver
        • People with kidney disease may need to take a lower dose.
        • Tagamet (Cimetidine) can cause states of intense confusion. This is usually reversible when you stop taking Tagamet (Cimetidine). If you have kidney problems, you may need a different dose to prevent this increased risk for side effects. However, stopping Tagamet (Cimetidine) completely may be necessary.
        • People with kidney disease on dialysis may need to take a lower dose or avoid use. Your doctor can do blood tests to see if it's safe to use.
        • If you have kidney or hyperparathyroid disease Tums (Calcium Carbonate) can build up in your blood. This may can cause toxic levels of calcium in your body. This is more likely if you have severe kidney disease (defined as a kidney function blood test called GFR of less than 30ml/min). If you have severe kidney disease or are on kidney dialysis don't use Tums (Calcium Carbonate); a different antacid would be better for you.
        • Tums (Calcium Carbonate) contains calcium. Calcium can be an ingredient in some kidney stones. If you have had kidney stones in the past (especially the calcium-containing kind) be careful using Tums (Calcium Carbonate). Use the lowest dose for the shortest time possible or just play it safe and use a different antacid instead.
        No specific sex-related info.No specific sex-related info.
        No specific sleep-related info.No specific sleep-related info.
        No specific weight-related info.No specific weight-related info.
        Upsides and benefits
        • Most people can take Cimetidine without any noticeable day-to-day side effects.
        • Cimetidine lasts longer than many other antacids like Maalox and Tums, and you only need to take it once or twice a day.
        • You can take it in combination with a quick-acting antacid (like Maalox or Tums) if you need relief right away.
        • Available as both a generic and over-the-counter option, so it's pretty affordable.
        • Works really fast.
        • Available over the counter without a prescription.
        • Cheap.
        Downsides and risks
        • Other antacids like Maalox, Tums, or Rolaids often start to work more quickly than Cimetidine.
        • Medication like omeprazole (proton pump inhibitors) works better at healing and preventing stomach ulcers than medication like Cimetidine (H2 blockers).
        • Has more drug interactions than zantac and pepcid.
        • Although rare, Cimetidine can cause large breasts or impotence for men who need to use high doses for 6 months or more. It's reversible though and should go away when you stop or if you change medication.
        • Doesn't last very long.
        • Other antacids like Zantac (H2 blockers) and omeprazole (proton pump inhibitors) can work better and last longer.
        • Some chalky aftertaste.
        Tips from our pharmacists for people taking the medication
        • Works best if you take it with a full glass of water.
        • Starts working in one hour.
        • People with kidney disease may need to take a lower dose.
        • Tell your doctor all of the medications that you use before taking Cimetidine to avoid drug interactions.
        • If heartburn doesn't improve or lasts more than 2 weeks, talk to your doctor.
        • Take at the first sign of discomfort.
        • You might need to take more than once a day but pay attention to the instructions on your bottle to avoid overdosing.
        • You need to separate Tums from some medications to avoid interactions.
        • People with kidney disease on dialysis may need to take a lower dose or avoid use. Your doctor can do blood tests to see if it's safe to use.
        • Don't take if you have high blood calcium levels.
        • If heartburn doesn't improve or lasts more than 2 weeks, talk to your doctor.
        Learn more
        More about TagametSide effectsReviews & ratingsAlternativesFDA package insert
        More about TumsSide effectsReviews & ratingsAlternativesFDA package insert