Ammonium tetrathiomolybdate is primarily used in the treatment of Wilson's disease, a genetic disorder that causes copper to accumulate in the body. It works by binding to excess copper, forming a complex that can be excreted, thereby reducing copper levels in tissues. Additionally, it is employed in research settings to study copper metabolism and its role in biological systems. Preliminary studies also explore its potential in treating certain cancers, as it inhibits angiogenesis by chelating copper, which is essential for new blood vessel formation in tumors; however, this application remains in the research and development stage. In industrial applications, it serves as a precursor for the synthesis of molybdenum sulfide compounds, which are utilized as catalysts and lubricants. Its ability to chelate metals also makes it useful in analytical chemistry for metal ion detection and separation.