During aging, we observe decrease in the content of the growth hormone (GH) and insulin-like growth factor I, estrogen deficiency in women, decrease in the testosterone level in men, decrease in the lean body weight, increase in the fat weight and other changes linked to the growth hormone deficiency. In not elderly people, treatment of the growth hormone deficiency with the recombinant human growth hormone (rhGH) improves the proportion of muscle tissue to fat tissue in the organism, enhances muscle strength, physical endurance and the solidity of bones, lowers blood level of cholesterol and the risk of cardiovascular diseases. However, the rhGH therapy is often accompanied with carpal tunnel syndrome, peripheral edema, articular pain and swelling, gynecomastia, glucose intolerance. Probably, it also increases the risk of cancer development. Experimental data show that, in elderly men, low testosterone level correlates with the loss of the lean body weight and muscle strength, and with increase of the fat weight. Probably, low testosterone level is also associated with the decrease in the solidity of bones, loss of insulin sensitivity, cognitive and emotional decline, and reduction of sexual function. It is necessary to carry out additional investigations which will reveal how growth hormone influence organism’s functioning, what its positive and negative effects are. Replenishment of testosterone in elderly men shows some positive effects at each of those parameters.