Dexlansoprazole (trade names Dexilant) is a prescription medication used to treat acid-related damage to the lining of the esophagus (erosive esophagitis, or EE) and heartburn related to gastroesophageal reflux disease (GERD) in adults. Dexlansoprazole belongs to a group of drugs called proton pump inhibitors (PPI), which reduce the amount of acid in the stomach.