GnRH has been extensively tested as a diagnostic agent in differentiating between the causes of hypogonadism. In patients with complete pituitary destruction, GnRH does not stimulate gonadotrophic hormone release, but in patients with lesser degrees of pituitary dysfunction associated with hypogonadism, GnRH may induce a gonadotrophin response within the normal range.
Long-standing hypothalamic dysfunction can lead to poor or absent pituitary responsiveness. For these reasons therefore, a single bolus injection of GnRH is a poor differential diagnostic agent.
