N-Acetyl-3,5-diiodo-L-tyrosine ethyl ester is a specialty chemical used in biochemical and pharmacological research, particularly for studying thyroid hormone metabolism. Its iodine-containing structure, which resembles thyroid hormones, allows it to serve as a marker or precursor in the synthesis of related compounds. It is also applied in the development of drugs and chemicals related to the endocrine system, with a focus on thyroid gland function and hormone regulation mechanisms in the body.