Reassessment of the human chorionic gonadotropin stimulation test in hypogonadal males

Eight normal and 17 hypogonadal males were injected with human chorionic gonadotropin (hCG). In normal males at 48 hr testosterone and estradiol became, respectively, 160% and 338% of basal values. In hypogonadal males at 48 hr testosterone and estradiol became respectively, 211% and 127% of basal values. No changes occurred in serum thyroid stimulating hormone (TSH), serum thyroxine (T4), and tri-iodothyronine (T3). The success of long-term therapy with hCG in five patients was predicted by the test.