Molecular pharmacology is the study of how drugs interact with cellular molecules to affect biological functions at the molecular level. It focuses on understanding the mechanisms by which drugs bind to specific targets such as receptors, enzymes, ion channels, or nucleic acids to produce therapeutic or adverse effects. This field combines molecular biology, biochemistry, and pharmacology to explore cellular signaling pathways, gene expression, and receptor-ligand interactions. Molecular pharmacology plays a vital role in drug discovery and development by identifying how drugs work and how they can be improved. It also helps in understanding variations in drug responses due to genetic differences, supporting the development of personalized medicine. Techniques used include molecular docking, protein analysis, and cell-based assays. This knowledge leads to safer, more effective, and targeted treatments for various diseases.