Tamoxifen treatment of oligozoospermia: a re-evaluation of its effects including additional sperm function tests

Summary Because of previous contradictory results, we reevaluted the effects of tamoxifen on 29 men presenting with idiopathic oligozoospermia. To determine whether a possible increase in sperm concentration might be correlated with an improvement of sperm quality, the hamster ovum penetration (HOP) test and the hypo-osmotic swelling (HOS) test were included as additional tests of sperm function. Patients were treated with tamoxifen (20 mg/day) for 3 months. From 4 weeks until the end of the study, tamoxifen had a significant effect (P<0.001) on blood levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), and estradiol (E₂). Prolactin (PRL) concentrations were not altered significantly (P>0.05). There was no significant improvement (P>0.05) of conventional semen parameters (volume, concentration, motility, morphology), and of HOP and HOS test results. The lack of correlation between a rise in hormone levels and improvement of sperm quality suggests that tamoxifen is of questionable value in men with idiopathic oligozoospermia.