With age comes a diminished capacity for cellular protein synthesis, a decline in immune function, an increase in fat mass, a loss of muscle mass and strength and a decrease in bone mineral density.

Age-related disability is synonymous weakness, impaired mobility, balance, and poor endurance. In the very elderly it is called physical frailty and includes falls fractures, impairment in activities of daily living, and loss of independence. Loss of muscle strength causes by aging of muscle fibers and their innervations, osteoarthritis, sedentary lifestyle and chronic debilitating diseases are all important factors in the process of frailty. There is however considerable variation in the effect of aging on healthy individuals, with some persons exhibiting extensive alteration in physiological function with age and others little or none. Traditionally, this aging process has been considered to be physiological and unavoidable but in rest years. An increasing numbers of people are not willing to accept the grim stereotype of aging as an unalterable process of decline and loss. Hormones are partly responsible for this change in attitude. Now a numbers of accept of aging process of the endocrine system invite the development of “routine” medical intervention programs offering long term replacement therapy with one or more hormones, In order to delay the aging process and to allow to us to live for a longer period in a relatively intact state.