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 an over-the-counter medicine 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 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. Use all heartburn medications as directed. #1 Doctor and Gastroenterologist recommendedBlocks heartburn for up to 24 hours Do not take for more than 14 days or more often than every 4 months unless directed by a doctor