Class B1 G protein-coupled receptors (GPCRs) represent a significant subgroup of the GPCR family, which play key roles in cellular signaling. These receptors regulate diverse physiological processes, including metabolism, immune responses, and neuroendocrine signaling. Notably, class B1 GPCRs bind peptide hormones and are implicated in various diseases, from metabolic disorders such as diabetes to inflammatory conditions and certain cancers. Understanding the structural and functional dynamics of class B1 GPCRs is essential for the development of targeted therapies and drug design, making them a focus of extensive biomedical research. In this review, we summarize the current information regarding the dynamic structures and functions of class B1 GPCRs, elucidating their crucial roles in various physiological processes and the molecular mechanisms underlying their interactions with ligands. We explore the architectural details of the N-terminal extracellular domain (ECD) and 7-transmembrane domain (TMD), focusing on how these structural elements contribute to the receptor's conformational flexibility. This structural plasticity serves as a target for designing novel therapeutics, allowing for more precise and effective treatment of metabolic, cardiovascular, and neuroendocrine disorders.