The main organ involved in detoxification in the body is the liver. It plays a critical role in metabolizing and eliminating harmful substances, including drugs, alcohol, and metabolic waste. The liver processes these substances and transforms them into less toxic forms, which can then be excreted through urine or bile. Furthermore, the liver synthesizes important proteins, regulates glucose levels, and helps in digestion, showcasing its multifunctional importance in maintaining overall health and homeostasis in the body.