Nexium 40mg (esomeprazole) tablets are a proton pump inhibitor (PPI) used to reduce the amount of stomach acid produced. It is commonly prescribed to treat conditions such as gastroesophageal reflux disease (GERD), stomach ulcers, and erosive esophagitis, helping to alleviate symptoms like heartburn and acid reflux. Nexium promotes healing of the stomach lining and esophagus and is also used to prevent ulcers in individuals taking certain pain medications. It should be taken as directed by your doctor, typically before a meal, for optimal effectiveness.