This reprint collects original research articles, comprehensive reviews, and an editorial focused on the characterization and therapeutic potential of bioactive compounds. The contributions examine not only natural products and synthetic and semisynthetic molecules but also repurposed pharmacological agents, with particular attention paid to their molecular mechanisms of action, the specific metabolic impacts, and organism-level responses. A central theme is the application of integrative omics methodologies, including metabolomics, proteomics, and transcriptomics, in order to dissect complex biochemical networks and pathophysiological processes. Together, these studies illustrate how bioactive compounds influence key signaling cascades, immune modulation, metabolic homeostasis, and cellular stress responses. The volume provides a scientifically rigorous overview of emerging strategies that support precision medicine, innovative drug discovery, and translational biomedical research.