Used primarily as a radiocontrast agent for imaging the gallbladder and biliary system. Administered orally, it helps visualize the liver, gallbladder, and bile ducts in X-ray studies due to its high iodine content, which blocks X-rays and enhances image contrast. It is especially useful in diagnosing gallstones and other biliary obstructions. Also used in some cases to manage certain thyroid disorders by inhibiting thyroid hormone release. Its use has declined with the rise of ultrasound and other imaging technologies, but it remains an option in specific diagnostic settings.