Hormone Replacement: The Fountain of Youth?

Natural aging brings reduced production of growth and sex hormones, beginning in middle age, with noticeable physiologic changes by the sixth or seventh decade of life: reduced muscle mass, energy, and exercise capacity and alterations in sexual function. Hormones and hormone precursors have been investigated to delay changes in body composition, strength, and physical and cognitive function. Menopausal hormone therapy is effective for vasomotor and genitourinary symptoms. Testosterone is effective in men with hypogonadism and declines in physiologic function. The lack of clinical studies evaluating the long-term effects and risks of hormone replacement limits its use.