L-Selenomethionine is widely used as a dietary supplement due to its role as a bioavailable source of selenium, an essential trace mineral. It is commonly incorporated into nutritional products to support antioxidant defense systems, as selenium is a key component of enzymes like glutathione peroxidase, which helps protect cells from oxidative damage. This compound is particularly beneficial for individuals with selenium deficiency or those seeking to boost their immune function and thyroid health, as selenium plays a critical role in thyroid hormone metabolism. Additionally, L-Selenomethionine is utilized in research studies to investigate the effects of selenium on chronic diseases, cancer prevention, and cognitive health. Its organic form is preferred over inorganic selenium compounds due to its superior absorption and retention in the body. In agriculture, it is used as an ingredient in animal feed to increase selenium levels in animal products such as meat and milk, benefiting consumer health.