Novo Nordisk has developed a subcutaneous formulation of semaglutide (Ozempic), a modified human glucagon-like peptide-1 (GLP-1) analogue, for the treatment of type 2 diabetes mellitus. It has been developed using Novo Nordisk's proprietary protein-acylation technology, and is administered using an injection device. Semaglutide lowers blood glucose by stimulating the release of insulin and also lowers body weight. Once-weekly subcutaneous semaglutide has recently been approved in the US, Puerto Rico and Canada, and has received a positive opinion in the EU for the treatment of patients with type 2 diabetes. It will be launched as the OzempicPen, a pre-filled device. Semaglutide is also under regulatory review in Japan and Switzerland for the treatment of type 2 diabetes. Clinical development for obesity, non-alcoholic steatohepatitis and non-alcoholic fatty liver disease is underway worldwide. This article summarizes the milestones in the development of semaglutide leading to this first approval for type 2 diabetes.