There are now four agents in the new class of glucose-lowering agents called dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) available in the UK. They are, in order of launch in the UK, sitagliptin, vildagliptin, saxagliptin and linagliptin. Several others are in the pipeline and are likely to be launched before long. This article will discuss their place in treating diabetes and the differences between them.