Prilosec is a brand-name drug that people commonly use to treat stomach and esophagus conditions caused by too much acid, such as heartburn, acid reflux, gastroesophageal reflux disease (GERD), and ulcers.
Prilosec belongs to a class of drugs known as proton pump inhibitors (PPIs). It’s available as an oral suspension that you take mixed with water. Prilosec also comes as a generic drug called omeprazole and as an over-the-counter (OTC) version that comes as an oral tablet.
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How long does it take for Prilosec to kick in?
How long it takes Prilosec to kick in will depend on the form of Prilosec you’re taking and the condition you’re taking it for.
When you take a dose of Prilosec, its acid-reducing effects may last between 24 to 72 hours, but it may take longer for symptoms of your condition to clear up.
When taken for something like heartburn or GERD, prescription Prilosec may take up to 4 days to fully kick in. For conditions like ulcers, it may take a few weeks or months for symptoms to get better.
If you’re taking Prilosec OTC, you should see your doctor if your symptoms have not cleared up after 14 days.
When should I take Prilosec?
Taking Prilosec around the same time each day helps keep a steady level of the drug in your body and helps ensure that it works effectively.
Doctors typically suggest taking Prilosec 30 to 60 minutes before eating your first meal of the day, usually in the morning. This is because the food causes your stomach to produce acid. And PPIs like Prilosec work best when your stomach is actively producing acid.
If you have been instructed to take Prilosec two times per day, it is best to take it 30 to 60 minutes before eating breakfast and 30 to 60 minutes before eating dinner. Prilosec may not work as well if you take it right before bed.
Your doctor will help you determine the best time to take Prilosec based on your symptoms. It is important to follow your doctor’s guidance.
Can I take Prilosec after eating?
Prilosec works best when you take it before eating. If you take it after eating, it may not work as effectively. This is because the food will cause longer for the medication to get absorbed in your bloodstream.
If you’ve tried taking Prilosec before eating but still experience indigestion pain after eating, talk to your doctor. They may suggest taking antacids after eating.

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Get free cardHow long should I wait to eat after taking Prilosec?
Doctors typically suggest taking Prilosec on an empty stomach. They recommend waiting for 30 to 60 minutes before you eat anything.
When you wait for 30 to 60 minutes to eat, the drug has enough time to fully enter your bloodstream. It will most likely kick in right around the time that your stomach starts producing acid. As a reminder, eating food causes your stomach to produce acid, and PPIs work best when your stomach is actively producing this acid.
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Summary
For conditions like heartburn, acid reflux, and GERD, Prilosec may take 1 to 4 days to work. For conditions like ulcers, it may take a few weeks or months for symptoms to fully go away.
It’s important to take Prilosec consistently and at the right time to ensure it works most effectively. Prilosec typically works best when you take it 30 to 60 minutes before breakfast if you take it once daily. If you take it twice daily, doctors may recommend taking it 30 to 60 minutes before breakfast and 30 to 60 minutes before dinner.