L,L-Dityrosine is widely used in biochemical research as a marker for oxidative stress. It is formed when tyrosine residues in proteins are exposed to reactive oxygen species, making it a valuable indicator for studying cellular damage and aging processes. In medical research, it helps in understanding diseases related to oxidative stress, such as neurodegenerative disorders and cardiovascular conditions. Additionally, it is utilized in the development of diagnostic tools to assess the extent of oxidative damage in biological samples. Its role in protein cross-linking also makes it relevant in studies focused on tissue repair and structural integrity of proteins.