Compare to Prilosec OTC. Stop the painful burning sensation of frequent heartburn before it begins with Amazon Basic Care Omeprazole Delayed Release Tablets 20 mg. Omeprazole is the #1 Active Ingredient for Frequent Heartburn (based on iRi sales volume among PPI products sold in the United States, for the 52 weeks ending 01/01/23). When used as directed for 14 days, Omeprazole prevents heartburn that is frequent in nature and provides long-lasting, 24-hour relief so you can enjoy every moment with family and friends. This heartburn medicine may take one to four days for full effect, although some people get complete relief of symptoms within 24 hours. Proton Pump Inhibitors (PPIs), like Omeprazole, work differently from antacid tablets and other acid reducer pills. These heartburn relief treatments only neutralize the stomach acid and provide shorter relief (less than 24 hours). Omeprazole stops acid production at the source, preventing the acid that causes heartburn symptoms for relief that lasts all day and night. This heartburn medicine is a 14-day course of treatment that should be taken once every 24 hours for 14 days to treat frequent heartburn flare-ups. For adults 18 years and older suffering from frequent heartburn that occurs two or more days a week.