Used primarily in the treatment of Wilson’s disease, a disorder of copper metabolism, where it acts as a chelating agent to promote copper excretion. Also employed in the management of severe rheumatoid arthritis due to its immunomodulatory effects, particularly in patients unresponsive to conventional therapy. Additionally, it is used to dissolve cystine kidney stones by forming a more soluble complex with cystine in the urine. Its ability to interfere with collagen cross-linking makes it useful in reducing fibrosis in certain connective tissue disorders, though this application is less common.