All GLP-1 receptor agonists share a common mechanism, activation of the GLP-1 receptor.
GLP-1 receptors are expressed by β cells, cells in the peripheral and central nervous systems, the heart and vasculature, kidney, lung, and GI mucosa. Binding of agonists to the GLP-1 receptor activates the cyclic AMP-PKA pathway and several GEFs (guanine nucleotide exchange factors).
GLP-1 receptor activation also initiates signaling via PKC and PI3K and alters the activity of several ion channels.
In β cells, the end result of these actions is increased insulin biosynthesis and exocytosis in a glucose-dependent manner.