With one Prilosec OTC pill each morning, block your heartburn for a full 24 hours. Heartburn happens when stomach acid refluxes into the esophagus. Prilosec OTC s delayed-release formula helps it pass through the tough stomach acid, preventing excess acid production to block frequent heartburn. Some other heartburn relief treatments only neutralize the stomach acid after it s already been produced and provide shorter relief (less than 24 hours). Prilosec OTC is the 1 Doctor and Gastroenterologist recommended frequent heartburn medicine for over 15 years. Prilosec OTC s active ingredient, 20 mg of delayed released omeprazole, works to fight heartburn differently from treatments like acid controllers/H2s or antacids. Omeprazole blocks heartburn for a full 24 hours after taking one pill each morning. Omeprazole is a proton pump inhibitor (PPI) and PPIs are a powerful class of frequent heartburn medicines. PPIs block heartburn by preventing excess acid production something that antacids just can t do. With 1 Prilosec OTC pill each morning, block heartburn for 24 hours, unlike antacids which last only 1-3 hours. Zero heartburn is possible with Prilosec OTC. Not for immediate relief. Take one pill per day as directed to treat frequent heartburn. May take 1 to 4 days for full effect. Compared to how antacids for heartburn. Use all heartburn medications as directed. Do not take for more than 14 days or more often than every 4 months unless directed by a doctor. Not for immediate relief. IQVIA ProVoice Survey, 2005 2022. Check with insurance provider