HGH does two things. First, it has a localized effect on adipose cells; it causes lipolysis. Second, it stimulates the release of IGF-1 from peripheral tissues. IGF-1 is then bound by IGFBP (the most dominant being IGFBP-3) and transported to the tissues to stimulate growth (hyperplasia-not hypertrophy like AAS).
As we age, our bodies become resistent to our own hormones--especially insulin, HGH, Growth Hormone Releasing Hormone, LH, FSH, etc. We have overcome the HPTA resistence/lack of function by supplementing with Testosterone and other AAS. There does not seem to be much resistence to Testos. at any age--the side effects are the problem. HGH resistence is a problem. And even Dr. Ronald Klatz, the father of rHGH therapy, has suggested that IGF-1 supplementation is the future as far as HGH is concerned. Long R3 IGF-1 sidesteps the problems of IGF-1's short half-life and it sidesteps the HGH resistance problem. It even side steps the genetic/envornmental problem of a lack of IGFBP-3. You need lots of IGFBP-3 to keep IGF-1 active longer. Not surprisingly, top athletes have LOW free IGF-1 levels and high IGFBP-3 levels. Long R3 IGF-1 works longer regardless of the IGFBP-3 levels. More research needs to be done on IGF-1 and its role in metabolism, weight control, aging, etc.
As far as availability, it is widely available to researchers/doctors. Assuming using 50mcg EOD and every other month (because of upregulation), the costs aren't as bad as originally thought. Each month will cost about $1900.00. Obviously, everyone needs to deicdie if this investment is affordable or if it is too rich.