"Restoring testosterone production in men may be as effective as replacing it without compromising their fertility. Two phase III clinical trials show that a drug that restores the bodys natural production of testosterone has no negative effect on a mans sperm count while a topical testosterone gel causes a significant drop. The findings which are published in BJU International could change the way men are treated for low testosterone.  While testosterone replacement therapy can boost mens energy levels sex drive and mood the treatment can fool the body into thinking that it is producing enough testosterone so that it in turn starts making less of its own. This can result in a significant decrease in sperm countleading to infertilitybecause the body needs its own testosterone to produce sperm.  An alternative approach to testosterone replacement is based on restoring the bodys natural production of testosterone with drugs similar to those used to help women ovulate. Edward Kim MD urologist at the University of Tennessee Medical Center and Professor at the University of Tennessee Graduate School of Medicine in Knoxville and his colleagues compared such a drug called Enclomiphene citrate with testosterone replacement therapy Androgel in overweight men with low testosterone or hypogonadism. In the randomized studies  men started on . mg of oral enclomiphene citrate daily with  men being uptitrated to  mg  men received a topical . percent AndroGel and  men received a placebo. Over five months patients had  clinic visits with one overnight stay. The investigators found that Enclomiphene citrate restored blood testosterone levels to normal after  weeks while maintaining sperm concentrations whereas Androgel restored blood testosterone levels but caused marked reductions in sperm concentrations by suppressing the function of the testes.  One of the basic tenets in medicine is to do no harm. As this study has shown in a randomized doubleblind doubledummy placebocontrolled manner exogenous testosterone therapy with Androgel can clearly decrease sperm production and potentially impact fertility said Dr. Kim. This study confirmed that Enclomiphene can maintain spermatogenesis while restoring testosterone levels to normal.   Full citation Oral Enclomiphene Citrate Raises Testosterone and Preserves Sperm Counts in Obese Hypogonadal Men Unlike Topical Testosterone Restoration Instead of Replacement. Edward D. Kim Andrew McCullough and Jed Kaminetzky. BJU International Published Online October   DOI .bju..  URL Upon Publication httpdoi.wiley.com.bju. Author Contact To arrange an interview with the author please contact Susan Wyatt of the University of Tennessee Medical Centers press office at SWyattmc.utmck.edu mailtoSWyattmc.utmck.edu or   . About the Journal BJUI is a highly respected international medical journal that aims to provide the very highest standard of research and clinical information for the urological community promoting awareness of new advances and supporting best practice in urology. Every issue gives invaluable practical information in the form of original articles reviews comments translational science and surgical education articles on all aspects of urology.  About Wiley  Wiley is a global provider of knowledge and knowledgeenabled services that improve outcomes in areas of research professional practice and education. Through the Research segment the Company provides digital and print scientific technical medical and scholarly journals reference works books database services and advertising. The Professional Development segment provides digital and print books online assessment and training services and test prep and certification. In Education Wiley provides education solutions including online program management services for higher education institutions and course management tools for instructors and students as well as print and digital content. The Companys website can be accessed at http"