Changes in sperm morphology in normal men treated with danazol and testosterone

Abstract Thirty-five normal volunteers were administered different combinations of danazol and testosterone. Sperm count and sperm morphology were examined prior to, during and following drug administration. The number of volunteers in each group and drug assignment category appear in Table I. In all groups except the danazol placebo groups, a decrease in sperm counts occurred. The percentage of immature germ cells increased and the percentage of oval spermatozoa decreased. This was most pronounced in groups V (danazol 400 mg qd and testosterone enanthate 200 mg/mo) and VI (danazol 600 mg qd and testosterone enanthate 200 mg/mo). After discontinuation of treatment, the sperm count and the sperm morphology returned to pretreatment values within four months. The most effective treatment for suppression of spermatogenesis was danazol 600 mg daily and testosterone enanthate 200 mg i.m. monthly. When sperm count was suppressed to below 10 × 10 6 /ml, the sperm morphology showed about 70–90 percent immature forms. The appearance of spermatids only, and the absence of earlier germ cells such as spermatocytes and spermatogonia, suggests that danazol acts by inhibiting spermatogenesis at the spermatocyte spermatid level rather than by causing premature sloughing of the germinal epithelium.