This assay is useful in the diagnosis and differential diagnosis of Hyperandrogenism. It is a crucial sex steroid precursor. In conjunction with other androgenic precursors, it is used in the diagnosis / monitoring of Congenital Adrenal Hyperplasia. It is also useful in diagnosis of Premature adrenarche. Androstenedione response to ACTH may be useful in the differential diagnosis of androgen excess in women.