Much has been posted on this forum on the benefits of GH vs. the drawbacks in terms of human lifespan. I recall much of the drawbacks to increasing one's GH had been debunked by members here as well as those well-respected in the HRT community. But lately, there has been more and more research supporting the negative effects of increasing one's IGF-1 (decreased lifespan, cancer, CVD, diabetes, etc.) via various exogenous applications (increased protein intake, excess calories, exogenous HGH, etc.). Additional research also supports protein restriction [http://scientificpsychic.com/blog/?p=418] or cycling, [as I posted on here: http://www.allthingsmale.com/forum/showthread.php?21146-Protein-cycling-anyone], as increased protein intake boosts IGF-1 production [http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2673798/]. In the following recent article and documentary produced by the BBC, animals have been genetically engineered so their body produces very low levels of a IGF-1, high levels of which seem to lead to accelerated aging and age-related diseases, while low levels are protective. As levels of the IGF-1 drop, a number of repair genes appear to get switched on according to ongoing research by Professor Valter Longo of the University of Southern California who is also director of the USC Longevity Institute. article: http://www.bbc.co.uk/news/health-19112549 full documentary: http://www.youtube.com/watch?v=Pfna7nV7WaM But is the case against higher IGF-1 levels valid, as both inhibition of IGF-1 and lowered protein intake run counter to everything we learned from the HRT/anti-aging community [http://www.neogenantiaging.com/igf1-is-it-better-than-hgh/?] In fact, I believe A4M is still of the opinion that optimum IGF-1 blood levels are between 350 to 400 and that treatment is clinically indicated when IGF-1 blood levels drop below 200. This 2008 study supports the exact opposite of these latest rounds of research: http://www.sciencedaily.com/releases/2008/05/080527084252.htm Elderly men with higher activity of the hormone IGF-1--or insulin-growth factor 1--appear to have greater life expectancy and reduced cardiovascular risk, according to a new study. IGF-1 is a hormone similar in molecular structure to insulin. It is released from the liver and plays an important role in childhood growth and continues to have anabolic effects in adults. ... Subjects with the lowest IGF-1 function had a significantly higher mortality rate than subjects with the highest IGF-1 bioactivity. These results were especially significant in individuals who have a high risk to die from cardiovascular complications. And how does any of the argument against maintaining adequate levels of IGF-1 and protein consumption figure in with the strength, bodybuilding, and other fitness-minded crowd? We all know that too little protein - or worse - a strict vegan diet - will promote disease, decrease metabolism from too little lean body mass, etc. Based on this paradigm, anything we can do to keep GH and IGF-1 levels up will help us look and feel younger - but will such extend or decrease lifespan? It therefore goes without saying that there's a lot of contradictory science going on here. First off, it has been show that fasting, particularly intermittent fasting (IF), actually raises endogenous HGH. We know that dietary restriction (DR) reduces IGF-1, however, IF may not in cases in which calories are unrestricted: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC156352/ Given the above contention that IGF-1 inhibition via protein restriction (or protein cycling), or otherwise, can extend human lifespan, I would think most would side toward having a fantastic quality of life (which for me means plenty of lean mass, plenty of physical activity, and plenty of meat on my plate) than live a few extra, IGF-1 and protein-restricted years. Ideally, all of us want both the quality and quantity of life. But, is it possible? IGF-1 is not recognized as the ONLY true marker for GH activity. In fact, the following post suggests there is the possibility of a completely inverse relationship between increased GH levels and IGF-1 levels by using HGH secretagogues as opposed to exogenous HGH which, as we know from firsthand experience and otherwise, raises IGF-1: http://health.groups.yahoo.com/group/Rejuvenation/message/5453 Scientific abstracts showing GH and IGF-1 being completely independent of one another: http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(94)90181-3/abstract http://www.ncbi.nlm.nih.gov/pubmed/2245967 http://www.ncbi.nlm.nih.gov/pubmed/10941424 And this paper touting the benefits of a HGH secretagogue TD cream Trans-D-Tropin suggest the same: https://www.transd.com/truth_about_gh.php Perhaps the trick is to err on the side of caution and use secretagogue peptides that will simultaneously raise GH levels while not affecting IGF-1? Yet, it is unclear as to exactly which peptides will raise IGF-1. Anyone with some updated research on this, please post. At the end of the day, does it all come down to: It is better to live one day as a lion, than a lifetime as a mouse - OR - is there a legitimate method to obtain the positive benefits associated with increasing one's GH without the apparent age-reducing effects we are seeing more research substantiate with respect to increased IGF-1? Let's hear it from the experts!