This document discusses insulin, including its isolation in 1921 by Banting and Best, current production through recombinant DNA technology, and its synthesis from proinsulin. It also classifies and describes various oral hypoglycemic agents used to treat diabetes, including sulfonylureas, non-sulfonylureas, thiazolindiones, bisguanides, and alpha-glucosidase inhibitors. Sulfonylureas are discussed in more detail, noting their structure-activity relationships.