There's been mention of IGF-1 results stopping after 40, 50 and 60 days, thus leading most users to limit the lenght of time they're on it. Well for me what limits me the most is money but that's another story.
I'm reading another board and a lot of guys recommend 8, 12 weeks on IGF-1. Now they are mostly using receptor grade instead of media grade which is what we mostly have access to, so do I believe. Their logic for this is that most of the effects of hGH are mediated through IGF-1 and in their terms "you don't stop GH after 4 weeks, do you?" Nope, that's not the way GH is run. So... Could that be from the difference between receptor grade and media grade?
Anectodally, an old and now largely unavailable recipe for us in North America that replaces IGF-1 very nicely is the use of GH releasers along with an insulin releaser. As we know, GH + slin = IGF-1 through the magic of your friend Liver. This was mostly accomplished by using GHB, a great gh releaser, taken in a very sugary solution, which of course releases insulin. In the UK, and there may be some british members of this board, this is still widely done because it is a VERY inexpensive way to increase your IGF-1 production. I haven't tried this with Hexatropin or p-GH although my morning p-GH is immediately followed by a meal, which does release insulin. I have done the GHB & sugar thing, at high doses, for 10 consecutive months and my gains were very nice. I seemed like a gifted natural trainee rather than a juicer, gradually putting it on, more size than strength.
Now if my little IGF-1 recipe had stopped working after 6 or 8 weeks, there's no way I would have kept it up. Waking up in the middle of the night for my second GHB dose was quite the thing I tell you. But it was worth it IMO. So the question remains and can be summed up as this : how much evidence is there that results from IGF-1 administration diminish and stop after 6-8 weeks, and is this possibly related to a difference between media/receptor grades formulations?