Current and future development of glucagon-like peptide-1 receptor agonists, more commonly referred to as GLP-1 RAs, or simply as GLP-1s, involves complexities not only in formulation but in all areas of early-phase drug development. Developing and refining preclinical models for early efficacy signals, developing and validating the bioanalytical assays necessary for quantitation, and designing the clinical studies that deliver the most robust data in this innovative therapeutic area are all key elements of a drug development program.In this audiobook, we review the requirements for successful GLP-1 drug development, from the perspective of preclinical studies, clinical trials, manufacturing, and bioanalysis. Exclusive case studies are also presented.