I saw a report on the internet of a study conducted at the Mayo Clinic. It involved giving men age 65 to 85 HGH for a year and seeing the results. Like other similar studies the subjects showed the men gained muscle mass, lost body fat and had more energy. However there was one disturbing finding at the start of the test. None of the men aged 80 and older had any detectable HGH in them. One of the doctors conducting the study theorized that this was part of the body's natural defense mechanism to protect itself from an anabolic cancer cell growth stimulator. It dosen't look like HGH is a life extension drug, at least according to this study. Since cancer becomes more common as we get older. One wonders if this could apply to testosterone also at that age.