T-IR- Study to Understand the Effects of Testosterone and Estrogen on the Body's Response to the Hormone Insulin

Inclusion Criteria: * Prostate-specific antigen (PSA) ≤ 3 ng/mL * Age 25-55 years * Ability to understand the study, study procedures and provide informed consent * Serum total T \> 300 ng/dL * Normal reproductive history and exam * International Prostate Symptom Score (IPSS) \< 11 Exclusion Criteria: * A history of prostate cancer including suspicious digital rectal exam (DRE) or history of highgrade prostatic intraepithelial neoplasia (PIN) on prostate biopsy * Invasive therapy for benign prostatic hyperplasia (BPH) in the past * History of acute urinary retention in the previous 3 months * Current or recent past use of androgenic or anti-androgenic drugs, steroids or drugs which interfere with steroid metabolism (within the last 3 months) * Current use of statins or glucocorticoids * Severe systemic illness (renal, liver, cardiac, lung disease, cancer, diabetes mellitus) or skin disease * A history of or current breast cancer * Known, untreated obstructive sleep apnea * Hematocrit \> 50 or \< 34 * Hypersensitivity to any of the drugs used in the study * History of a bleeding disorder or anticoagulation * Participation in any other drug study within past 90 days * History of drug or alcohol abuse within the last 12 months * Weight \> 280 lbs. or BMI ≥ 33 * Desire for fertility in the next 6 months or current pregnant partner * Sperm concentration \<14 million/ml * Significant, uncontrolled hypertension (BP \>160/100 mmHg); subjects with well-controlled BP on medical therapy will be eligible to participate