Do antacids cause constipation?

You’re trying to relieve GI issues, not create new ones—but taking certain antacids can lead to constipation, especially if you’re taking them around the clock or using more than the recommended amount. Antacids containing calcium carbonate like TUMS, Pepto Bismol, and some proton pump inhibitors can cause constipation. Talk to your doctor if you think your antacid is making it more difficult for you to have regular bowel movements.

Do antacids help with gas?

Antacids can help with gas, but it’s not a symptom addressed by all OTC antacids. Proton pump inhibitors don’t specifically target gas and bloating, but antacids containing simethicone, bismuth subsalicylate, or magnesium can relieve gas symptoms in addition to reflux and indigestion.

When is the best time to take antacids?

Usually prior to eating, especially if you know you’re about to consume something that triggers your reflux or indigestion. Proton pump inhibitors, in particular, work best when taken before a meal. “Timing is important, as you need to take [these] 30 minutes before a meal and not at the time of the meal,” says Dr. Curtin. “By the time you take your first bite, the acid is already in your stomach waiting.” Chewable antacids, like TUMS, can definitely be taken after eating if you end up with an unexpectedly upset stomach. They can work quickly to relieve symptoms, but you might have better effects from taking them before a meal, too.

The 7 Best Antacids of 2021

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When heartburn or acid indigestion strikes, you need something that settles your stomach ASAP. It’s no fun to walk around feeling like you have your own personal fire-breathing dragon raging in your esophagus, and it’s even less fun to battle the burn while trying to work, exercise, drive through rush hour traffic, or sleep.

If you’re prone to bouts of GI distress, it’s smart to have a reliable over-the-counter antacid on hand that can provide quick relief. Why? Because these medications can decrease the amount of stomach acid you produce, says University of Missouri Health Care gastroenterologist Yezaz Ghouri, MD.

“The stomach normally produces hydrochloric acid to help digest food and kill bacteria or other organisms that may have been ingested along with the food,” Dr. Ghouri explains. “When there is an overproduction of the acid, it can lead to stomach discomfort.”

Overproduction of stomach acid can be caused by eating spicy foods, drinking too much caffeine or alcohol, and frequently taking NSAID pain relievers, as well as chronic conditions like peptic ulcer disease and gastroesophageal reflux disease (GERD).

Whatever the cause of your discomfort, antacids can often relieve and prevent painful episodes of heartburn and indigestion. Here are the six best OTC antacids for controlling your symptoms.

Our Top Picks

Best Overall:

Prilosec OTC at Amazon

It prides itself as the '#1 Doctor Recommended Brand' for heartburn relief.

Best Liquid Antacid:

Pepto Bismol Original at Amazon

Drink down some of the classic pink stuff to treat all kinds of upset stomach, including heartburn and indigestion.

Best Flavored Antacid:

TUMS Chewy Bites Antacid Tablets at Amazon

These tablets go down super smoothly, neutralizing all that uncomfortable acid brewing in your stomach.

Best Chewable Antacid:

Rolaids Extra Strength Antacid Chewable Tablets at Amazon

Offers an advanced formula that contains higher levels of acid-fighting minerals—calcium and magnesium.

Best for GERD:

Nexium 24HR Acid Reducer Heartburn Relief Capsules at Amazon

For GERD sufferers, Nexium 24HR can relieve and prevent symptoms on an ongoing basis.

Best for Kids:

Mylicon Children's Tummy Relief at Amazon

These gluten-free tablets are a smart choice for kids between the ages of two and 11.

Best With Added Benefits:

Maty’s All Natural Acid & Indigestion Relief at Amazon

A drug-free, all-natural alternative that can help you avoid interactions and side effects.

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Pros

Reduces stomach acid
Easy dosing schedule
One of the first proton pump inhibitors created

Cons

May not be as strong as some other brands
May not start working until 14 days

Prilosec, or omeprazole, belongs in the proton pump inhibitor category of antacid drugs, which means it reduces the amount of food-digesting acid produced by the cells in your stomach lining. It calls itself the “#1 Doctor Recommended Brand” for heartburn relief, and it’s Dr. Ghouri’s personal favorite, too.

“Omeprazole was one of the first antacids in the class of drugs called proton pump inhibitors, and while some of the newer ones like esomeprazole and dexlansoprazole are considered to be more potent, omeprazole is usually sufficient in controlling symptoms in a majority of cases,” Dr. Ghouri says.

The dosing for Prilosec OTC is simple: you take one pill a day for 14 days, every four months (or up to three times per year). It may take the full 14 days before you feel the full effects of the drug, but once it kicks in, you should have fewer symptoms of heartburn and acid indigestion until it’s time for your next course.

Active Ingredients: Omeprazole 20 mg | Dosage: 1 tablet every day for 14 days | Uses: Heartburn and acid indigestion

Expert Insight

“Proton pump inhibitors are the strongest medicines we have for reflux and other options should be tried first, including histamine blockers like famotidine.”

—Dr. Bryan Curtin, Director of The Center for Neurogastroenterology and GI Motility at Mercy Medical Center in Baltimore

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Pros

Coats the stomach
Soothes heartburn
Treats multiple symptoms, including diarrhea

Cons

Potent flavor
May cause constipation with overuse

There’s no OTC medication for sour stomach more iconic than Pepto Bismol, with its fluorescent pink color, chalky texture, and minty (or cherry) flavor. It’s been around forever, and that’s because it works. Dr. Ghouri recommends that people with mild, intermittent heartburn turn to this easy-to-find option, which treats nausea and diarrhea symptoms, too.

Pepto Bismol, or bismuth subsalicylate, is available in a few different formulations—like chewable tablets and capsules—but the liquid variety really cools the burn as it goes down. Once it’s ingested, it coats your stomach and reduces inflammation, which can also deter your stomach from overproducing acid.

You can take two tablespoons of the liquid every 30 to 60 minutes, as needed, for up to eight doses in 24 hours. Note that taking Pepto Bismol consistently can cause constipation. Additionally, speak to a doctor before giving Pepto Bismol to a child or teenager also exhibiting flu-like or chicken pox symptoms.

Active Ingredients: Bismuth subsalicylate 525 mg | Dosage: 30 mL every 30 minutes as needed, not exceeding 240 mL in 24 hours | Uses: Nausea, heartburn, indigestion, upset stomach, and diarrhea

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Pros

Easily chewable tablets
Smooth, fruity flavor

Cons

Neutralizes stomach acid but doesn’t prevent symptoms
May cause constipation with overuse

Let’s face it: you’re already queasy and uncomfortable, the last thing you want to do is choke down a gag-inducing medication in an attempt to feel better. This is where the smoothie variety of chewable TUMS really comes to the rescue; these tablets go down super smoothly, neutralizing all that uncomfortable acid brewing in your stomach.

TUMS Chewy Bites are made with calcium carbonate, a mineral that effectively reduces acid and performs a dozen other helpful tasks like cleaning your teeth, making your cakes rise, and, of course, strengthening your bones. Keep in mind, though, that too much can cause constipation, so stick to the recommended dosage.

Active Ingredients: Calcium carbonate 750 mg | Dosage: 2 to 4 tablets as needed, not exceeding 6 tablets in 24 hours | Uses: Heartburn and acid indigestion

Expert Insight

“Generally, patients [can] start by taking something like TUMS or Pepto Bismol since they are more readily available and don’t have too many side effects.”

—Bryan Curtin, M.D., Director of The Center for Neurogastroenterology and GI Motility at Mercy Medical Center in Baltimore

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Rolaids Extra Strength Antacid Chewable Tablets

Pros

Works quickly to reduce stomach acid
Magnesium can help with constipation
Multiple flavors and formulations

Cons

Neutralizes stomach acid but doesn’t prevent symptoms

If you’re a chronic sufferer of GI problems like diarrhea, constipation, bloating, and indigestion, you may have been told to increase your magnesium intake. That’s because magnesium improves your nerve and muscle function, and can go a long way toward smoothing out digestive hiccups.

Many products designed to treat acid reflux, heartburn, and indigestion contain magnesium, but we like Rolaids Extra Strength Tablets for quick, reliable relief. Each tablet contains 55 milligrams of magnesium plus 270 milligrams of calcium, making Rolaids a one-two punch when it comes to neutralizing and reducing stomach acid on the spot.

You can snag the extra strength tablets in either mint or fruit flavor, and take up to 10 tablets per day (two to four at a time) for two weeks, or as needed. Rolaids also offers an advanced formula that contains higher levels of magnesium and calcium, targeted at providing acid indigestion relief and relief from gas and bloating.

Active Ingredients: Calcium carbonate 675 mg, Magnesium hydroxide 135 mg | Dosage: 2 to 4 tablets as needed, not exceeding 10 tablets in 24 hours | Uses: Heartburn and acid indigestion

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Pros

Highly effective for reflux symptoms
Symptom prevention
Easy dosing schedule

Cons

May cause constipation
May not be safe for people with existing conditions

Gastroesophageal reflux disease is caused by stomach acid rising all the way up into your esophagus, throat, and mouth, and can cause a painful burning sensation, belching, and difficulty swallowing.

Although there are often lifestyle changes you can make to improve symptoms of GERD, many people find themselves turning to an OTC or prescription antacid to make life a little more comfortable. One of the common medications used is Nexium 24HR, or esomeprazole, a proton pump inhibitor that works in a similar way as Prilosec OTC. The main difference is that you’ll only take one pill per day for a 14-week treatment course since Nexium’s effects last longer.

Since GERD can be a debilitating condition that makes it difficult to eat, drink, exercise, sleep, or simply enjoy day-to-day life, it’s important to find lifestyle changes and effective medications that bring you relief. For GERD sufferers, Nexium 24HR can relieve and prevent symptoms on an ongoing basis.

Active Ingredients: Esomeprazole 20 mg | Dosage: 1 capsule every day for 14 days | Uses: Frequent or chronic heartburn

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Children's Mylicon Tummy Relief for Kids

Pros

Safe for kids as young as two years old
Reduces acid and fights gas

Cons

Can cause constipation with overuse

Some babies are born into this world with extra-sensitive stomachs, and as a parent, you need to know what treatments, remedies, and medications are safe for your little one’s tummy troubles.

Thankfully, Mylicon understands this parental dilemma; they’ve been making simethicone drops for babies suffering from painful gas between feedings for years. But they also offer a children’s antacid, so there’s a way to help older kids, too.

Containing acid-reducing calcium carbonate and gas-busting simethicone, the antacid works well for kids with occasional indigestion (like ones who overdo it on the ice cream cake) as well as for kids who have more frequent stomach aches.

The tablets are free of gluten, saccharin, alcohol, and artificial flavors. They can be used by kids between the ages of two and 11. Younger kids can take one tablet three times per day, and older kids can take two tablets up to six times per day.

Active Ingredients: Calcium carbonate 400 mg, Simethicone 40 mg | Dosage: 1 tablet every 8 hours for kids aged 2-5, 2 tablets every 4 hours for kids aged 6-11 | Uses: Bloating, gas, and indigestion in kids

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Maty’s All Natural Acid & Indigestion Relief

Pros

Drug-free, natural alternative
No aluminum, talc, dairy, or gluten
Safe to use every day

Cons

May not be effective as traditional products
Some users reported worsening of reflux symptoms

If you feel squeamish about the thought of adding more medications to your daily routine to treat your heartburn and indigestion symptoms, a drug-free, all-natural alternative like Maty’s could be a good option for you.

With tummy-friendly ingredients known to reduce stomach acid, relieve constipation, and reduce bloating, this supplement might help you prevent some of your most frequent symptoms—all while letting you reap the benefits of a few superfoods, like turmeric, ginger, and apple cider vinegar. While there isn’t a ton of evidence confirming the benefits of these ingredients, many researchers have suggested that these ingredients can relieve pain, reduce inflammation, boost your immune system, and improve circulation (in addition to potentially reliving your heartburn and indigestion).

One other reason you might want to give the natural route a try? If you take other medications contraindicated for use with many common OTC antacids or have experienced constipation with many other treatments, a drug-free option can help you avoid interactions and side effects.

Active Ingredients: None | Dosage: 2 capsules with meals or as needed | Uses: Heartburn and acid indigestion

Final Verdict

Prilosec OTC (view at Amazon) is Dr. Ghouri’s go-to recommendation for symptoms of indigestion because it works well and is available in a generic formulation, making it accessible and affordable. If your indigestion only pops up once in a while, treat it on the spot with a dose of Pepto Bismol (view at Amazon).

What to Look for in OTC Antacids

Your Symptom Needs:

Dr. Ghouri says there are three main categories of OTC antacids, and which one you use may depend on the severity of your symptoms.

If your symptoms are mild and intermittent, opt for a product with bismuth subsalicylate, calcium carbonate, or magnesium hydroxide.

If your symptoms are mild but persistent, choose an H2-receptor antagonist like famotidine.

If your symptoms are moderate to severe, you likely need a proton pump inhibitor like omeprazole or esomeprazole.

Dosage:

How often do you have symptoms? It’s an important question to answer when choosing an antacid, since different products last for different lengths of time. Some are 12 or 24-hour, meaning you’ll only need to take them once or twice per day, but others last just a few hours (so you’ll need to keep them handy for re-dosing, if necessary). If you only have heartburn when you eat certain foods, a short-acting antacid should work fine—but if your indigestion is chronic, you’ll want a longer-lasting formula.

Your Medical History:

Antacids aren’t safe for everyone to take, says Dr. Ghouri, and there may be side effects. Bismuth subsalicylate and calcium carbonate can cause constipation, while proton pump inhibitors carry a risk of bone fractures, vitamin deficiencies, and kidney disease, though this isn’t typical with short-term use. “The incidence of these severe side-effects is generally low and requires long-term use of these medications,” explains Dr. Ghouri. “In general, it is recommended to speak to your physician before initiating therapy with antacids, especially for the long term.”

Frequently Asked Questions

Do antacids cause constipation?

You’re trying to relieve GI issues, not create new ones—but taking certain antacids can lead to constipation, especially if you’re taking them around the clock or using more than the recommended amount.
Antacids containing calcium carbonate like TUMS, Pepto Bismol, and some proton pump inhibitors can cause constipation. Talk to your doctor if you think your antacid is making it more difficult for you to have regular bowel movements.
Do antacids help with gas?

Antacids can help with gas, but it’s not a symptom addressed by all OTC antacids. Proton pump inhibitors don’t specifically target gas and bloating, but antacids containing simethicone, bismuth subsalicylate, or magnesium can relieve gas symptoms in addition to reflux and indigestion.
When is the best time to take antacids?

Usually prior to eating, especially if you know you’re about to consume something that triggers your reflux or indigestion. Proton pump inhibitors, in particular, work best when taken before a meal.
“Timing is important, as you need to take [these] 30 minutes before a meal and not at the time of the meal,” says Dr. Curtin. “By the time you take your first bite, the acid is already in your stomach waiting.”
Chewable antacids, like TUMS, can definitely be taken after eating if you end up with an unexpectedly upset stomach. They can work quickly to relieve symptoms, but you might have better effects from taking them before a meal, too.

What Experts Say

“I generally would do a six to eight week trial of a proton pump inhibitor before declaring [it doesn’t work]. This is not a fast acting medication and needs to be in your system for at least six to eight weeks before seeing the full effect.”

—Bryan Curtin, M.D., Director of The Center for Neurogastroenterology and GI Motility at Mercy Medical Center in Baltimore

Why Trust Verywell Health?

Sarah Bradley has been writing health content since 2017—everything from product roundups and illness FAQs to nutrition explainers and the dish on diet trends. She knows how important it is to receive trustworthy and expert-approved advice about over-the-counter products that manage everyday health conditions, from GI issues and allergies to chronic headaches and joint pain.

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