Liraglutide is the first once-daily human GLP-1 analogue developed for the treatment of type 2 diabetes mellitus(T2DM). The half-life of liraglutide is 13 h following subcutaneous injection, making it suitable for once-daily dosing. Clinical data indicates improved beta cell function with liraglutide treatment in patients with T2DM. Liraglutide increases insulin secretion in a glucose-dependent manner, and improves first- and second-phase insulin responses. Liraglutide delays the rate of gastric emptying, reduces energy intake and exerts a moderate suppression on hunger as indicates by diverse appetite rating endpoints. Liraglutide dose not impair the counter-regulatory glucagons response to hypoglycaemia in patients with T2DM, which is consistent with the glucose-dependent action of liraglutide. Liraglutide was associated with no major or minor hypoglycaemia and was generally well tolerated, with the most common side-effect reported as mild, transient nausea. Liraglutide allows significantly more patients to achieve HbAlc targets compared with current treatment. Liraglutide significantly reduces weight in patients.