An insufficient level of testosterone in aging men and women is associated with a constellation of adverse conditions (cognitive decline, loss of muscle mass, osteopenia, decreased libido, changes in fat distribution, fragility, depression, a greater risk of fracture). Research has confirmed that supplementary testosterone can ameliorate those signs and symptoms in hypogonadic individuals, but the benefits and risks of that therapy remain controversial. The treatment of such patients should be based on knowledge of the physiologic effects of testosterone in the elderly, effective screening for testosterone deficiency accurate measurement of bioavailable levels of that hormone, and safe and effective treatment options, all of which are examined in this article. In designing hormone replacement regimens, the skill of a compounding pharmacist who can customize dose and dosage forms to answer individual medical needs and preferences can be instrumental in achieving the desired outcome.