The endocrine physiology of the climacteric supports a rationale for the concomitant replacement of androgen and estrogen following menopause. Clinical and research experience with estrogen-androgen hormone replacement therapy, as well as androgen-only therapy, suggests that the health benefit offered by androgen replacement exceeds the potential risk when treatment is properly managed. In this review, we concentrate on the effects of oral alkylated androgens. The virilizing effects (e.g., hirsutism, acne, voice change, and alopecia) of oral androgens are typically dose and duration dependent; androgen replacement at doses < or = 10 mg once daily administered for prolonged periods (> 6 months) produces masculinization effects that generally abate with dose reduction or discontinuation of treatment. No clinical sequelae or irreversible pathophysiologic effects have been associated with any virilization that may occur. Changes in lipoprotein metabolism associated with oral estrogen-androgen use include reduced total cholesterol levels and reduced high-density lipoprotein cholesterol levels which may reduce the long-term risk of cardiovascular disease. No clinically identifiable risk with respect to other cardiovascular variables, such as blood pressure, has been associated with the longterm administration of low doses of oral androgen. With regard to liver toxicity, reports of jaundice, peliosis hepatis, and hepatocellular carcinoma are extremely rare at the dose levels of androgen used in hormone replacement therapy, although individual sensitivity to the potential hepatotoxic effects of oral alkylated and nonalkylated androgen may vary considerably. Daily dosing with oral alkylated androgen in combination with estrogen is well tolerated. Retrospective and prospective studies involving the use of androgens alone and in combination with estrogens demonstrate that concerns about the adverse effects of androgen use associated with supraphysiologic, self-escalated doses in men do not apply to the much lower doses combined with estrogens for hormone replacement in postmenopausal women.