Why is illegal usage of HGH dangerous for health?

Human Growth Hormone (HGH) has been initially elaborated for clinical purposes. This medicine is recommended for treatment of children with growth disorders and adults that suffer from deficiency of growth hormone and associated troubles. But this medication is often abused. Numerous weightlifters and other athletes apply this medication for athletic purposes. Under laws of certain countries, including the USA, purchase and application of this product for non-therapeutic purposes are considered to be illegal.
However this medicine is illicit without any prescription, it is not a problem to obtain it. This drug is widely available at online pharmacies. Furthermore, steroid dealers sell this medication. Since it doesn’t cost much, many persons have possibility to purchase it.
Those who use HGH illegally abuse also other preparations. They are not limited just by illicit intake of this medicine. Which products are also used by consumers of HGH?
Some scientists decided to conduct a research connected with illegal usage of HGH. They enrolled 230 weightlifters aged 18-40 into the research. The specialists could determine that the most of these weightlifters took not only HGH but also anabolic-androgenic steroids and insulin-like growth factor-1. Moreover, many of them administered recreational drugs, such as cocaine, ecstasy, etc.
Which risks are faced by those that take high quantities of HGH long period of time? Unfortunately, unwanted results resulted from increased measures of this preparation are not studied sufficiently because physicians usually don’t recommend increased doses.  Increased doses are commonly used by those that take this medicine for performance-enhancing effects. But it is known that intake of increased dosages during prolonged period of time may result in severe undesirable consequences. This drug may negatively influence on various systems, including endocrine, respiratory, cardiovascular, etc. It is important to be very cautious because enhanced measures of this medicine are linked even with cancer.