The investigators plan to study 60 subjects. All of these subjects will be healthy older men between the ages of 60-85 years old who are not on testosterone therapy. Subjects that are screened who have any clinically significant abnormalities detected on their screening physical exam or laboratory testing (e.g. Prostate Specific Antigen > 4), who have a history of prostate cancer, polycythemia, or who cannot take testosterone will not be included.