Dexilant is a medicine used in the treatment of gastroesophageal reflux disease. The active ingredient of the medicine - dexlansoprazole - is used because it works as a proton pump inhibitor. This class of drug helps to reduce acid formation in the stomach by turning off acid producing cells.Dexilant is a prescription drug that used to treat gastroesophageal reflux disease (GERD), a condition whose primary symptom is the backward flow of acid from the stomach that causes heartburn and possible injury to the esophagus. Dexilant is also used to treat a persistent cough and inability to swallow. Dexilant may help heal the damage caused by acid in the stomach and esophagus and prevent ulcers. It can lower the risk of cancer of the esophagus as well. Dexilant is in a class of drugs known as proton pump inhibitors. It works by reducing the amount of acid produced in the stomach.