G protein-coupled receptors (GPCRs), also known as G-protein linked receptors, serpentine receptors, or heptahelical receptors, represent the largest superfamily of membrane proteins in the human genome. These integral membrane proteins possess seven membrane-spanning helices and function to transduce a diverse array of extracellular stimuli, including biogenic amines, peptides, hormones, neurotransmitters, ions, odorants, and photons, into intracellular signals. This transduction is facilitated by a ligand-induced conformational change in the GPCRs, which activates heterotrimeric G proteins (guanine nucleotide-binding proteins) essential for conveying the extracellular ligand signal to the cell's interior. G-proteins can be categorized based on homologous structure and common ligand subtypes. The regulatory impact of GPCRs spans physiological processes such as cell metabolism, differentiation, growth, neurotransmission, and sensory perception. Additionally, they are implicated in numerous diseases, including type 2 diabetes mellitus, obesity, depression, cancer, Alzheimer’s disease, and more, making them a prime drug target for various therapeutic interventions.