Potassium iodide is a chemical compound made up of potassium and iodine. It appears as a white or colorless crystalline solid and is often used in medicine and as a dietary supplement. In medical settings, it can help protect the thyroid gland from radiation exposure, particularly during nuclear emergencies. In addition to its protective role, potassium iodide is also used in various industrial applications, such as photography and the production of certain chemicals. It can be found in some over-the-counter supplements to provide iodine, which is essential for proper thyroid function and overall health.