H-36731: Finasteride in Management of Elevated Red Blood Cells

Inclusion Criteria: * Adult males 18 years of age or older * Currently is being treated for hypogonadism with testosterone therapy using injectable testosterone. * Must not have erythrocytosis (defined as a hematocrit of 52% or higher) attributable to other medication or medical condition * Agree not to initiate any other treatment for erectile dysfunction (ED), including herbal and over- the-counter (OTC) medications, for the duration of the study. * Must not already be taking finasteride or other 5-alpha reductase inhibitor Exclusion Criteria: * Men not currently using testosterone supplementation therapy or men on non-injectable testosterone therapy * Prior history of anabolic steroid use, but have not used for at least 6 months * Prior history of testosterone use, but have not used for at least 6 months * Men who are already taking finasteride * Untreated or inadequately treated hypothyroidism * Significant history of allergy and/or sensitivity to the drug products or excipients, including sensitivity to testosterone and/or finasteride * Current use of any medications, herbal, and/or nutritional supplements that can interfere with testosterone level * Currently receiving treatment with cancer chemotherapy or anti-androgens * Any contraindication to testosterone therapy or finasteride * History of luteinizing hormone-releasing hormone antagonist or agonist treatment * History of clomiphene treatment in 6 months prior to Visit 1