5-Hydroxylansoprazole is a major metabolite of lansoprazole, a proton pump inhibitor (PPI) widely prescribed for gastrointestinal conditions such as gastroesophageal reflux disease (GERD), peptic ulcers, and Zollinger-Ellison syndrome. Formed via hepatic hydroxylation of lansoprazole, it plays a key role in the drug's metabolic pathway, contributing to its pharmacokinetics and safety profile. This compound is primarily utilized in pharmaceutical research to study the metabolism of lansoprazole and support the development of more effective therapies for acid-related disorders. It is not used directly as a therapeutic agent.