The discovery of insulin in the early 1920s also stimulated a search for oral medications to control blood sugar. Some of the first successful products reached the market in the 1950s including two classes of drugs, sulfonylureas and buguanides, that remain an important part of oral diabetes medications. The sulfonylureas, which stimulate the pancreas to produce more insulin, were first used as antibacterial agents but were banned when they caused dangerously low blood sugar levels (hypoglycemia). The byguanides are related to guanidine, a chemical found in goat’s rue (Galega officianalis) an old folk remedy for diabetes. This latter class of drugs improved the ability of insulin to move sugar into cells, thus lowering blood sugar levels.
Illustration of Galega officianalis from Flora von Deutschland, Österreich und der Schweiz by Otto WillhelmThomé, 1885