Trilostane-d3 is a deuterium-substituted isotope-labeled compound of Trilostane, which is used primarily as a quantitative tracer.Trilostane is a competitive and specific inhibitor of 3-beta-hydroxysteroid dehydrogenase (3β-HSD), with the advantage of oral activity.Trilostane reduces the synthesis of steroid hormones by inhibiting the activity of 3β-HSD, and can be Used in studies of Cushing's syndrome (hypercortisolism), Con's syndrome (hyperaldosteronism), and postmenopausal breast cancer.