The most simple testing of the hypothalamus-hypophysis unit can be carried out with ovulation releasers such as antiestrogens; these simultaneously provide a therapeutical effect. In case of failure, dynamic functional tests are to be carried out two weeks after the attempted ovulation release in order to determine the hypophyseal reserves in gonadotropin (LH-RH) and prolactin. This point in time corresponds to the expected luteinic phase. Lack of estrogens, hyperprolactinemia and disorders of the gonadotropic partial functions can be assessed simultaneously with this method. Gestagen-testing can then evaluate estrogen activity in the specific organ and exclude organic disorders. At present, we have nearly reached the point of enacting a causal therapy for functional sterility.