title: Chronic treatment with finasteride daily does not affect spermatogenesis or semen production in young men.
abstract: OBJECTIVE
  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.
  
  
  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.
  
  
  RESULTS
  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.
authors.affiliation: Department of Obstetrics and Gynecology, University of California, Davis, USA.
authors.forename: J W
authors.initials: JW
authors.lastname: Overstreet
authors.forename: V L
authors.initials: VL
authors.lastname: Fuh
authors.forename: J
authors.initials: J
authors.lastname: Gould
authors.forename: S S
authors.initials: SS
authors.lastname: Howards
authors.forename: M M
authors.initials: MM
authors.lastname: Lieber
authors.forename: W
authors.initials: W
authors.lastname: Hellstrom
authors.forename: S
authors.initials: S
authors.lastname: Shapiro
authors.forename: P
authors.initials: P
authors.lastname: Carroll
authors.forename: R S
authors.initials: RS
authors.lastname: Corfman
authors.forename: S
authors.initials: S
authors.lastname: Petrou
authors.forename: R
authors.initials: R
authors.lastname: Lewis
authors.forename: P
authors.initials: P
authors.lastname: Toth
authors.forename: T
authors.initials: T
authors.lastname: Shown
authors.forename: J
authors.initials: J
authors.lastname: Roy
authors.forename: J P
authors.initials: JP
authors.lastname: Jarow
authors.forename: J
authors.initials: J
authors.lastname: Bonilla
authors.forename: C A
authors.initials: CA
authors.lastname: Jacobsen
authors.forename: D Z
authors.initials: DZ
authors.lastname: Wang
authors.forename: K D
authors.initials: KD
authors.lastname: Kaufman
mesh_terms: D000328:Adult; D000367:Age Factors; D000505:Alopecia / Q000188:drug therapy; D004334:Drug Administration Schedule; D004791:Enzyme Inhibitors / Q000008:administration & dosage*; D018120:Finasteride / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D012661:Semen / Q000187:drug effects*; D013091:Spermatogenesis / Q000187:drug effects*; D013997:Time Factors
chemical_list: D004791:Enzyme Inhibitors; D018120:Finasteride