Compare to Prilosec OTC. Stop the painful burning sensation of frequent heartburn before it begins with Member's Mark(TM) 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). Stop Acid Production At The Source 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...