In individuals with obesity and prediabetes, liraglutide reduces fasting and postprandial glucose levels within 2 weeks of treatment independently of weight loss, and this glucose-lowering effect is not replicated by increasing endogenous GLP-1 via sitagliptin or by caloric restriction alone, indicating a unique pharmacological action of GLP-1 receptor agonism.

Liraglutide binds to GLP-1 receptors on liver, muscle, fat, and pancreas cells, which turns down glucose production by the liver and helps muscle and fat take up more glucose from the blood. At the same time, it stops the pancreas from releasing too much glucagon, a hormone that tells the liver to make more glucose. This dual action quickly lowers blood sugar without needing weight loss.