A Guide to Proton Pump Inhibitors (PPIs)

Medically Reviewed By Alyssa Walton, PharmD
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Proton pump inhibitors (PPIs) are drugs that reduce acid production in the stomach. They can aid in treating various conditions, such as acid reflux or esophagitis. PPIs are some of the most common prescription medications in the United States. However, they can potentially cause adverse effects. Your doctor will help you determine the best medication for you based on your individual circumstances.

Read on to learn more about what PPIs do, what conditions they can treat, and what side effects they may cause.

What do proton pump inhibitors do?

A packet of proton pump inhibitor pills
Marc Tran/Stocksy United

PPIs decrease acid production in the stomach by interfering with parietal cells. These cells contain the “proton pump” enzyme, which plays a role in the final step of stomach acid secretion.

PPIs are also anti-inflammatory, working against inflammatory proteins called cytokines. This makes PPIs helpful in certain conditions that can cause inflammation in the esophagus, such as eosinophilic esophagitis.

The primary use for PPIs is treating conditions related to acid production in the body. Below are some common conditions for which doctors might recommend PPIs.

Gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD), or acid reflux, involves frequent and chronic episodes of stomach acid moving upward into the esophagus. This reflux can cause heartburn, throat irritation, and vomiting.

GERD is one of the most common digestive disorders in the U.S. Researchers estimate that up to 20% of people may experience it.

Learn more about GERD.

Helicobacter pylori infection

Helicobacter pylori (H. pylori) is a type of bacteria that can enter the body and cause an infection in the stomach. Researchers do not know exactly how H. pylori spread. However, they believe that contaminated food or contact with body fluids containing it may play a role.

Treatment for an H. pylori infection can consist of antibiotics and PPIs. H. pylori can also contribute to other conditions requiring PPIs, such as peptic ulcer disease and gastritis.

Learn more about H. pylori.

Peptic ulcer disease

In peptic ulcer disease, open sores called ulcers form in the stomach or upper part of the small intestine. Various factors can play a role in developing this condition, including nonsteroidal inflammatory drug (NSAID) use or an H. pylori infection.

Peptic ulcer disease can cause abdominal pain, bloating, or unexpected weight changes.

Learn more about peptic ulcer disease.


Gastritis is a group of conditions that cause inflammation in the stomach lining. H. pylori infections commonly cause gastritis. NSAID or alcohol use may also contribute to developing gastritis.

PPIs are not the main treatment for gastritis. However, doctors may prescribe them alongside antibiotics for cases resulting from an H. pylori infection.

Learn more about gastritis.


Esophagitis refers to inflammation of the esophagus. It can result from multiple factors, such as GERD, infection, or trauma. People with esophagitis may experience chest pain and difficulty swallowing.

Doctors break down esophagitis into several subtypes, including:

  • reflux esophagitis
  • eosinophilic esophagitis
  • medication-induced esophagitis
  • radiation esophagitis
  • infectious esophagitis

PPIs can be beneficial in treating esophagitis due to their acid-blocking and anti-inflammatory effects.

Learn more about esophagitis.

Zollinger-Ellison syndrome

People with Zollinger-Ellison syndrome develop one or more tumors, usually in the pancreas or upper part of the small intestine. These tumors increase stomach acid production. This syndrome can lead to GERD or peptic ulcer disease.

Zollinger-Ellison syndrome may require lifelong PPI use.

What are some common proton pump inhibitors?

According to researchers, omeprazole (Prilosec) is one of 10 drugs that doctors most commonly prescribe in the U.S. Other PPIs that the Food and Drug Administration (FDA) has approved include:

While many PPIs come as tablets or capsules, some may be available as a suspension or IV formulation.

What are some potential side effects of proton pump inhibitors?

While PPIs are generally safe in the short term, long-term use or high dosages may cause adverse side effects. These may include:

In addition, the FDA states that long-term use or high dosages of PPIs could increase the risk of bone fractures. This risk is relatively low with short-term use.

Other frequently asked questions

Here are a few other common questions people may ask about PPIs. Alyssa Walton, PharmD, has reviewed the answers.

What is the most common proton pump inhibitor?

Omeprazole is one of the most common PPIs. It is among the top 10 most commonly prescribed drugs in the U.S.

How long does it take for proton pump inhibitors to start working?

It may take a few days for PPIs to take maximum effect.

Are proton pump inhibitors safe?

In the short term, most people have no difficulty tolerating PPIs. However, high doses or long-term use may cause adverse effects, such as vitamin deficiency, rebound acid secretion, or infection.


PPIs are effective medications for managing conditions that increase stomach acid production. People with GERD, peptic ulcer disease, and other conditions may experience symptom relief with PPIs.

However, using PPIs for long periods or taking them at higher doses may lead to adverse side effects. Your doctor will be able to help you assess possible risks.

Contact your doctor to discuss PPIs and how they may benefit you.

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Medical Reviewer: Alyssa Walton, PharmD
Last Review Date: 2022 Sep 22
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
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