I've just been prescribed Omeprazole for acid reflux. I've to take one 20mg tablet a day. I've only had two doses and still don't feel much better. How long does it take to start to feel better on. I've to take one 20mg tablet a day. After taking my first omeprazole, then eating breakfast, I experienced the same painful heartburn and sore stomach area. Does it take a while to work? How does omeprazole work? Omeprazole is a type of medicine called a proton pump inhibitor (PPI). Proton pumps are tiny substances in the lining of the stomach that help it make acid to digest food. DS1 is almost 6 and has been prescribed omeprazole for his stomach troubles. One doc said it takes a while to work and then the next said it works quite quickly. How Long Does Omeprazole Take To Work? How long does it take for omeprazole to work, and what are the implictions of taking it? Answer. Many people report that they get relief from one pill. Common Questions and Answers about How does omeprazole work prilosec Now she has heartburn almost everyday, at first the doctor gave her pantoprazole that didn't work and now she takes omeprazole , but after eating she still has heartburn almost everyday. 1. What is FDA announcing today? 2. What is Prilosec OTC used to treat? 3. How does Prilosec OTC work? 4. Will Prilosec OTC work as well as the prescription strength Prilosec? When I was in deep pain, Omeprazole 40mg dose 3 times a day did not work. Next day I took half tea-spoon Cayenne Pepper mixed in warm water and had this recipe 3 times with single dose of Omeprazole 40mg - It got under control. But keep doing this until you come back to 10mg Omeprazole. Does omeprazole work well for acid reflux? Updated 12 Aug 2016 • 3 answers How long does it take for omeprazole take to work after being changing from ranitidine? Prilosec doesn't work immediately, as it can take from one to four days before it's entirely effective. On the other hand, some people find total relief of heartburn symptoms within 24 hours.