One theory of aging is that we simply need to replace our collapsing hormones to youthful levels and then weight management, mood, memory, erectile function and all over things good will return with a vengeance. Of course, the reality is much more complex and replacement with HGH is one of those. HGH (Human Growth Hormone) is one of the few hormones that has really struggled in the research as I will show below. Here are Five Great Reason to Think Twice about HGH (Growth Hormone) Therapy and possibly even consider it dangerous for some men:
1. Increase in IGF-1. If you're young, increasing IGF-1 may not be a significant risk. However, as we age and accumulate DNA, estradiol increases, enzyme activity slows down, etc., cancer becomes much more of a risk and a concern. A little less than half of all men will get cancer statistically and IGF-1 has been found to play a significant role in many of the common epithelial ones. What does this half to do with HGH therapy? Well, giving a man exogenous growth hormone will increase his levels of IGF-1. For example, one study on the subject found that the IGF-1 levels of the men tripled when given HGH. 
As some of you know, this is probably going to be good for building muscle (hypertrophy). However, rememember that the "GF" in IGF-1 stands for "growth factor" and it has the potential to supercharge cancer cells according to a lot of research. In fact, lower IGF-1 levels are one of the most powerful anti-aging markers and this has been verifed in many species. One of the other reasons for this is that increasing IGF-1 levels is associated with increased risk for diabetes, something we will discuss below.
NEWS FLASH: IGF-1 on the scalp may be a cure for baldness according to a recent study on mice.  As far as I know, it is not available yet as a treatment in men.
2. Increase in Lp(a). One of the biggest risk factors for atherosclerosis (arterial plaque) is Lp(a). Lp(a) is also very hard on endothelial function, i.e. blood flow and thus can directly impact your bedroom performance. (See my reviews on the plaque reversers: Track Your Plaque and Heal Your Heart. And , interestingly enough, HGH therapy increases Lp(a) and IGF-1 decreases Lp(a).  This will likely not bode well for your arteries.
3. Incresased Risk of Diabetes. As I mentioned above, increasing IGF-1 levels increases the risk for adult onset diabetes. This is probably the reason that HGH Therapy increases the risk for diabetes according to one study of senior overweight men. 
4. Possible Increased Rates of Death and Dying. European researchers look at the long term mortality rates of children who had received recombinant human growth hormone (rGH) in childhood. They found that the rate of death was significantly increased in certain key areas and this was especially true for those who received higher dosages, thus indicating some "dose dependent" action. The authors concluded that "bone tumor-related mortality was increased. An increase in mortality due to diseases of the circulatory system or subarachnoid or intracerebral hemorrhage was observed." 
5. Nasty Side Effects. One of the studies above found that "persons treated with GH were significantly more likely to experience soft tissue edema, arthralgias, carpal tunnel syndrome, and gynecomastia."
CONCLUSION: HGH is devil and angel at the same time. On the one hand, it has some very impressive benefits: it decreases fat levels and can boost muscle a bit. It also can lower cholesterol levels and increase skin thickness. At the same time, though, it appears to put you in harm's way for diabetes, hemorrhages and possibly atherosclerosis and cancer. There are other more natural ways to boost your growth hormone, something I cover in my page on Lifestyle Methods to Increase Human Growth Hormone and Sleep and Growth Hormone.
1) NEJM, Jul 5 1993, 323(1), "Effects of human growth hormone in men over 60 years old"
2) Mechanisms of Ageing and Development, Feb 2005, 126(2):305-307, "Do deficiencies in growth hormone and insulin-like growth factor-1 (IGF-1) shorten or prolong longevity?"
3) Growth Hormone and IGF Research, Aprâ€“Jun 2014, 24(2-3):89â€“94, "Exogenous IGF-1 promotes hair growth by stimulating cell proliferation and down regulating TGF-Î²1 in C57BL/6 mice in vivo"
4) Eur J Endocrinol, 1997 Apr, 136(4):377-81, "Growth hormone increases and insulin-like growth factor-I decreases circulating lipoprotein(a)"
5) Ann Intern Med, 2007 Jan 16, 146(2):104-15, "Systematic review: the safety and efficacy of growth hormone in the healthy elderly"
6) J Clin Endocrinol Metab, 2012 Feb, 97(2):416-25, "Long-term mortality after recombinant growth hormone treatment for isolated growth hormone deficiency or childhood short stature: preliminary report of the French SAGhE study.