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How Prilosec OTC Works to Stop Frequent Heartburn

Learn about how Prilosec OTC works and why.

Frequent heartburn sufferers know the burning sensation in the chest all too well, especially after a particularly spicy meal or a second cup of coffee as a mid-afternoon pick-me up. Heartburn is uncomfortable, and once it starts, you want relief. The good news: You can tackle the discomfort from frequent heartburn altogether. Prilosec OTC can stop heartburn before it begins, providing 24-hour heartburn protection with one pill a day.*

How Prilosec OTC Works

When you eat, millions of tiny pumps in your stomach lining create acid to break down food. Normally, your lower esophageal sphincter (LES) opens and closes to let food pass from your esophagus into your stomach. When your LES (lower esophageal sphincter) relaxes, excess acids can flow up, or reflux, into your esophagus. This can create the painful sensation of heartburn.

Prilosec OTC works by directly blocking many of the active stomach pumps that produce acid before they start. Its unique delayed-release formula helps it pass through tough stomach acids. With Prilosec OTC, you can block the acid that causes frequent heartburn for 24 hours with 1 pill a day.* 

How to Take Prilosec OTC

Prilosec OTC should be taken once a day for up to 14 days, up to three times per year (or every four months). Take one pill a day with a glass of water before eating in the morning. When starting a course, know that it can take 1-4 days for full effect. Some users feel relief as soon as 24 hours after the first pill—but if that’s not the case for you, stay the course and take the entire 14 days of dosing. Prilosec OTC isn’t meant for immediate relief, but one pill a day can provide 24 hours of relief.*

If you feel you need Prilosec OTC for any time beyond that, consult with your doctor. You want to make sure you’re not missing a bigger health problem, like GERD. Do not take for more than 14 days or more often than every 4 months unless directed by a doctor.

What’s the active ingredient in Prilosec OTC?

Prilosec OTC is a proton pump inhibitor (PPI). The way the active ingredient, omeprazole, in Prilosec OTC works to fight heartburn sets it in a whole separate class from other treatments such as histamine blockers or antacids histamine blockers or antacids.

History of Prilosec OTC as Proven and Trusted Frequent Heartburn Medicine

Prilosec OTC has a history of trust as the first and original OTC frequent heartburn medicine.


1989: Prilosec is introduced as the first prescription proton pump inhibitor (PPI).

2003: Prilosec OTC becomes the first PPI available over-the-counter.

2004: Prilosec OTC became the #1-selling heartburn medicine to treat frequent heartburn.‡

2005: Prilosec OTC is named the #1 doctor and gastroenterologist-recommended OTC acid reducer…and still is.†^

2006: Prilosec OTC is named the #1 pharmacist-recommended OTC heartburn medicine…and still is.‡

2014: Prilosec OTC has effectively blocked heartburn for over 30 million patient treatments.**

There's a reason over 30 million heartburn sufferers** have tried Prilosec OTC to block frequent heartburn before it begins.* Since the beginning, we’ve led the way in OTC frequent heartburn treatments. We were first on the market and have continued to provide relief to frequent heartburn sufferers with our trusted formula. Don’t believe it for yourself? Listen to what Prilosec OTC users say about it.

Experience what zero heartburn* feels like by joining the Prilosec OTC Two-Week Challenge. Sign-up here for $3 off to help get you started, plus 14 days of tips, tricks and reminders. Just two weeks, zero heartburn* and 100% satisfaction or your money back...What do you have to lose?