- J Urol 1999 Oct;162(4):1295-300
Chronic treatment with finasteride daily does not affect spermatogenesis or semen
production in young men.
Overstreet JW, Fuh VL, Gould J, Howards SS, Lieber MM, Hellstrom W, Shapiro S,
Carroll P, Corfman RS, Petrou S, Lewis R, Toth P, Shown T, Roy J, Jarow JP, Bonilla J,
Jacobsen CA, Wang DZ, Kaufman KD
Department of Obstetrics and Gynecology, University of California, Davis, USA.
PURPOSE: Finasteride, an oral type 2, 5alpha-reductase inhibitor, is used
in 1 mg. daily doses for the treatment of male pattern hair loss. A dose of 5 mg.
finasteride daily reduces ejaculate volume by approximately 25%, and reduces prostate
volume by approximately 20% and serum prostate specific antigen (PSA) by approximately 50%
in men with benign prostatic hyperplasia. To our knowledge no data exist on the effect of
1 mg. finasteride daily on ejaculate volume or other semen parameters, or on the prostate
in young men. Therefore, we studied the potential effect and reversibility of effect of 1
mg. finasteride daily on spermatogenesis, semen production, the prostate
and serum PSA in young men.
- MATERIALS AND METHODS: In this double-blind, placebo
controlled multicenter study 181 men 19 to 41 years old were randomized to receive 1 mg.
finasteride or placebo for 48 weeks followed by a 60-week off-drug period. Of the 181 men
79 were included in a subset for the collection and analysis of sequential semen samples.
There were no significant effects of 1 mg. finasteride on sperm concentration, total sperm
per ejaculate, sperm motility or morphology. Ejaculate volume in subjects on finasteride
decreased 0.3 ml. (-11%) compared to a decrease of 0.2 ml. (-8%) for placebo, with a
median between treatment group difference of -0.03 ml. (1%, 90% confidence interval -10.4
to 13.1, p = 0.915). There were significant but small decreases in prostate volume (-2.6%)
and serum PSA (-0.2 ng./ml.) in the finasteride group, which reversed on discontinuation
of the drug.
- CONCLUSIONS: Treatment with 1 mg. finasteride daily
for 48 weeks did not affect spermatogenesis or semen production in young men. The effects
of 1 mg. finasteride daily on prostate volume and serum PSA in young men without benign
prostatic hyperplasia were small and reversible on discontinuation of the drug.