Amidinothiourea is primarily used in biochemical research as a reagent for studying enzyme inhibition, particularly in the context of understanding metabolic pathways. It acts as a competitive inhibitor for enzymes like arginase, which plays a role in the urea cycle, making it valuable for investigating nitrogen metabolism and related disorders. Additionally, it has been explored for its potential in synthesizing heterocyclic compounds, which are important in pharmaceutical development. Its ability to interact with metal ions also makes it useful in analytical chemistry for metal ion detection and separation processes.