Omeprazole is an acid reducer available in over-the-counter (OTC) medicines that treat frequent heartburn (i.e., symptoms occur two or more days a week). Omeprazole is part of a group of acid reducers called proton pump inhibitors, or PPIs. It can be the only ingredient in heartburn medicines that provide long-lasting relief of symptoms, or it can be found in medicines that contain an additional active ingredient that helps with the absorption of omeprazole.

Symptoms Treated

Symptoms Treated

More specifically: 


Common Products

  • Zegerid OTC®
  • Store Brands (ex. Walmart’s “Equate” store brand or CVS Health store brand)

Dosing Information

Different types of products containing this active ingredient have different strengths. That’s why it is always important to read and follow the Drug Facts label. Most medicines warn against use of an active ingredient for longer than 7-10 days. Stop use and ask a doctor if symptoms persist.

Safety Guide

Safety Guide

Omeprazole is approved by the U.S. Food and Drug Administration (FDA) and is safe and effective when used according to the Drug Facts label. You should follow the recommended course of treatment for 14 days. You may repeat the 14-day course every four months, if necessary.

Ask a healthcare provider before use if:

  • You are taking the blood-thinning drug warfarin.
  • You are using an antifungal or anti-yeast medicine.
  • You are taking the anxiety medicine diazepam.
  • You are taking the heart medicine digoxin.
  • You are taking the immune system medicine tacrolimus.
  • You are taking the HIV infection medicine atazanavir.
  • You have had heartburn for more than three months.
  • Your heartburn is accompanied by lightheadedness, sweating, or dizziness.
  • You are experiencing chest or shoulder pain with shortness of breath; sweating; pain spreading to your arms, neck, or shoulders; or lightheadedness.
  • You have frequent chest pain, wheezing, unexplained weight loss, nausea or vomiting, or stomach pain.
  • You are pregnant or breastfeeding.
  • Talk to a healthcare provider before giving an OTC medicine containing omeprazole to a child or adolescent under the age of 18.

Do not use if:

  • You are allergic to omeprazole.
  • You have trouble or pain swallowing food, are vomiting with blood, or have bloody or black stools.

Stop use and ask a doctor if:

  • Your heartburn continues or gets worse.
  • You need to take the product for more than 14 days.
  • You need to take more than one course of treatment every four months.
  • You take too much. Immediately contact a healthcare provider or the poison control national helpline at 800.222.1222.

What are the side effects of omeprazole?

  • Headache
  • Nausea
  • Vomiting
  • Diarrhea
  • Stomach pain
  • Gas