Inhibition of spermatogenesis in men using various combinations of oral progestagens and percutaneous or oral androgens.

Eight men (experiment 1) requesting male contraception received a daily oral dose of 20 mg medroxyprogesterone acetate (MPA) combined with 125 mg percutaneous dihydrotestosterone (DHT). Three months later the mean sperm count was only diminished slightly; the replacement of DHT for four men by percutaneous testosterone at the same concentration led to a dramatic fall in sperm count. For 6-18 months all men were treated with MPA plus percutaneous testosterone (250 mg daily). The latter dose restored physiological levels of plasma testosterone. Follicle-stimulating hormone levels were inhibited more severely than in the DHT-treated group, whereas LH levels were variable. Azoospermia was achieved and maintained in six cases; two men were oligozoospermic and in one case a moderate secondary rise in the sperm count was observed. Twelve volunteers (experiment 2) received a daily oral dose of either 5 or 10 mg norethisterone acetate plus percutaneous testosterone (250 mg daily). All of them achieved azoospermia within 2 months, but two subjects later exhibited a partial restoration in sperm count. Follicle-stimulating hormone and LH levels were inhibited more severely than in the first experiment. The sperm count and gonadotrophin levels returned to initial values within 6 months after cessation of the treatment in both experiments. No side-effects were noted concerning blood parameters, libido or body weight. However, several female partners had elevated levels of plasma testosterone. In experiment 3 (13 volunteers), percutaneous testosterone was replaced by oral testosterone undecanoate (160 mg daily). Only seven men were azoospermic and most of them had lowered levels of plasma testosterone. Thus, the combination of percutaneous testosterone and oral progestagens appears to be the most convenient for male hormonal contraception.