There is ample evidence to support the safety of growth hormone replacement therapy in growth hormone deficient adults (GHDA). In fact, Dr. Bengtsson has said, “When one does not abuse or overdose human growth hormone, there is simply NO evidence suggesting that human growth hormone replacement therapy causes ANY LONG TERM side effects.” (Hormone Research, 43, p 93-99, 1995, emphasis added) Therefore, in August of 1996, the FDA approved the use of hGH in growth hormone deficient adults. Because the body composition changes and IGF-I levels are similar in a GHDA and an older adult, we believe it is likely that the same safety profile pertains. Moreover, none of the NIA longer term studies of growth hormone replacement in older adults were stopped because of adverse effects. Finally, data has been published showing no adverse effects in a small number of growth hormone deficient adults on therapy for 10 years.
You may have read about the result of a study done by Maxime Papadakis, MD, at Stanford University in which another group of elderly men were given hGH and a high incidence of side effects occurred. These men were given hGH in much higher doses than necessary to get the body composition changes expected and it was given only three times a week. Many studies have been done on GHDAs and it is now known that the subcutaneous hGH injections must be given once or twice a day at a 50 to 25 percent lower dose.
Similar side effects were reported in patients in the NIA study patients on lower doses, but we think this is because of the age at which the growth hormone was started--all patients were over 65 years of age. A study in which men between the ages of 48 and 66 were given higher doses than in the NIA study had a low level of side effects while losing more body fat and gaining more lean muscle. How can this be explained? We think that this is because the majority of the decline in growth hormone secretion takes place before age 50 and therefore it should start to be replaced at a younger age than 65 or 70 when the body has been with a very low level of GH for decades.
When GH replacement is started in younger patients we have seen very few side effects. When started in older patients, it must be started at low doses and very gradually increased while being monitored closely.