Assuming cost is not an issue (and I am not saying that is the case) at what IGF-1 level do people consider supplementing with HGH to increase muscle mass. I have read that at any IGF-1 level less than 360, people can benefit from supplementing (not sure I beleive that). What is type of HGH is generally preferred? Do you have to worry about shutting down your own HGH production? Can anyone recommend a good thread to learn more? Thanks.