BERKELEY, CA (UroToday.com) - Our initial study “Finasteride Use in the Male Infertility Population: Effects on Semen and Hormonal Parameters”, was published in Fertility and Sterility in 2013. In this study, we found that finasteride, even at low doses, caused reduced sperm counts in some infertile men. While only 27 men were taking finasteride in our cohort, sperm counts improved dramatically (mean 11.6 fold increase) following finasteride discontinuation.