There is consistent improvement in this parameter with a usual 10% increase in lean body mass and a 5 to 10% decrease in body fat. Fat loss was greatest in the abdominal region. The alterations in body composition are reversed. The lean body mass increases as the adipose tissue decreases. This accounts for the fact that there may not always be an overall weight loss because of the increased muscle mass. In addition, human growth hormone affects the liver, kidneys, spleen, skin and bone, and is protective against atrophy by causing re-growth of tissue.

Growth hormone induces decomposition of adipose tissue. The adipose cell volume will decrease significantly. Metabolism is increased which results in the degradation of fat. In addition, cholesterol is lowered.

Growth hormone restores abnormal low levels of extracellular fluid. This cellular dehydration is implicated in many of the signs of aging. By replenishing this extracellular water, skin becomes thicker and wrinkles become less noticeable. Also, there is normalization of kidney function and improvement in sweating capacity.

During growth hormone therapy, there is a definite improvement in bone density. One study showed an increased bone mass of 2% per year.

There is an increase in muscle mass, which accounts for the improved ability to exercise with a concomitant increase in strength. There is also an increase in cardiac output. There is an increase in maximum oxygen uptake with a concomitant improvement in cardiac function.

Until recently, the supply of growth hormone was scarce because it had to be obtained from the pituitary gland of cadavers. This hormone is now available in large supply due to genetic engineering techniques that have been developed through recombinant DNA technology. HGH, also known, as Somatotropin is the most abundant hormone secreted by the pituitary gland. It produces at a rate that peaks during adolescence when accelerated growth occurs. Daily growth hormone secretion diminishes with age to the extent that a 60-year-old may secrete 25% of the HGH secreted by a 20-year-old. Growth hormone is primarily released in pulses that take place during the beginning phases of sleep, then it is quickly converted in the liver to its powerful growth promoting metabolite, Insulin-like Growth Factor type 1 (IGF1) ­ also known as somatomedin C. IGF1 elicits most of the effects associated with growth hormone and is measured in the blood to determine the level of growth hormone secretion.

     Human growth hormone has been shown in some studies to have side effects, which include carpal tunnel syndrome, arthritis and edema. This was experienced only when high doses were given. Numerous studies have shown that side effects can be avoided by slow initial administration, proper monitoring of levels and administration on a daily basis in what is called a low-dose, high frequency method. Some researchers have used growth hormone injections twice daily. Recent research has shown that the majority of naturally produced HGH is pulsed from the pituitary gland at night. This has lead to studies showing that a once a day injection at night seems to have the most beneficial effect, as evidenced by raising the somatomedin-C levels of protein produced by the liver. Human growth hormone cannot be measured directly unless extremely sensitive test are used. Therefore, the somatomedin-C (or insulin growth factor1, IGF-1) is most commonly used as an indirect measurement of growth hormone. However, this method is, at times, widely insensitive due to the natural daily fluctuation in hormone level. Although somatomedin-C is frequently used to monitor HGH, it is still not an exact measurement. However, more importantly, the somatomedin-C level is used to make sure that the amount of growth hormone administration is not in excess, which in turn will prevent any of the minor side effects. In summary, when the correct method of administration is employed and the levels monitored correctly, there will be no side effects.