The protocol was designed to address the hypothesis that oral testosterone enanthate plus dutasteride can suppress the secretion of LH and FSH after four weeks of administration. In addition, we will compare the gonadotropin suppression mediated by a dose of testosterone enanthate (400 mg twice daily) that would be expected to maintain the serum testosterone in the normal range throughout the day, with the same dose (800 mg once daily) administered once daily. This larger once-daily dose is expected to result in a higher peak and lower trough by the end of the dosing interval

This study will be carried out in a double-blinded fashion, so neither the subject nor the investigator will be aware of treatment assignment during the study. This protocol is designed to address the hypothesis that oral testosterone enanthate plus dutasteride can suppress the secretion of LH and FSH after four weeks of administration. In addition, we will compare the gonadotropin suppression mediated by a dose of testosterone enanthate (400 mg twice daily) that would be expected to maintain the serum testosterone in the normal range throughout the day, with the same dose (800 mg once daily) administered once daily. This larger once-daily dose is expected to result in a higher peak and lower trough by the end of the dosing interval. Secondary endpoints in this study include the ability of oral testosterone enanthate plus dutasteride to maintain short-term androgen-mediated endpoints such as mood and sexual function over the 4-week treatment period as well as weekly measures of safety, including blood counts, PSA and liver and kidney function.

Inclusion Criteria:

• Males between 18 to 55 years of age
• In good general health based on normal screening evaluation (consisting of a medical history, physical exam, normal serum chemistry, hematology, and baseline hormone levels)
• Subject must agree not to participate in another research drug study for the duration of the study
• Subject must agree to not donate blood during the study
• Subject must be willing to comply with the study protocol and procedures

Exclusion Criteria:

• Men in poor general health, with abnormal blood results (clinical laboratory tests or hormone values)
• A known history of alcohol or drug abuse
• A history of testicular disease or severe testicular trauma,
• A history of bleeding disorders or current use of anti-coagulants
• A history of sleep apnea and/or major psychiatric disorders
• A body-mass index greater than 35,
• A history of or current use of testosterone
• Infertility