Glipizide is an oral medium-to-long acting anti-diabetic drug from the sulfonylurea class. It is classified as a second generation Sulfonylurea, which means that it undergoes enterohepatic circulation. The structure on the R2 group is a much larger cyclo or aromatic group compared to the 1st generation sulfonylureas. This leads to a once a day dosing that is much less than the first generation, about 100 fold.

Mechanism of action is produced by blocking potassium K+ channels in the Beta cells of the Islets of Langerhans. By partially blocking the K+ channels, you will increase the time the cell spends in the Calcium release stage of cell signaling leading to an increase in calcium. The increase in Calcium will initiate more Insulin release from each Beta cell.

Originally available in 1984, it is marketed by Pfizer under the brand name Glucotrol® in the USA, where Pfizer sells Glucotrol in doses of 5 and 10 milligrams and Glucotrol XL (an extended release form of glipizide) in doses of 2.5, 5, and 10 milligrams. Other companies sell generic forms of glipizide, most commonly extended release tablets of 5 and 10 milligrams.