Streptozotocin (Streptozocin, STZ, Zanosar®) is a naturally occurring chemical that is particularly toxic to the insulin-producing beta cells of the pancreas in mammals. It is used in medicine for treating certain cancers of the Islets of Langerhans and used in medical research to produce an animal model for hyperglycemia in a large dose as well as Type 1 diabetes with multiple low doses.