Like I said it's a difficult question to answer due to the complex nature of IGF1 as it relates to GH usage, and the multitude of contributing factors that can hold the number down. Like everything involving the body it's also not a standardized XYZ thing. You and I could run the exact same amount, and take the exact same compounds and test completely differently. 4ius of GH is a decent amount, but whether or not it's enough to significantly raise IGF1 levels is debatable. Personally I don't think it's enough to increase it very much, but that's just my own opinion on it bro.
What do your estrogen levels look like? Higher levels of estrogen also can keep IGF #s lower. You already stated that you're on Tren, and Tren definitely impedes IGF. I'd come off the Tren, and then bang away on the GH at your current dose of 10iu a day for a good 2 months, and then go back and take another look at the IGF # to see where it's at. I'd be willing to bet you that # increases (provided you don't have anything else going on medically), but even then you aren't likely to see a HUGE increase in that IGF#. When you said your IGF was "normal" what was the #? I wish I could afford to run strictly Pharm grade cuz I'd love to be able to compare generics to Pharm grade as it relates to IGF. When I first started hitting GH on a regular basis I was expecting to see my IGF # double at a min, but even at 10-15ius a day of generics the best I've been able to do is raise it by 101 points which I consider a success. Like you I've seen the benefits of staying fuller and super lean (with T4), but have been repeatedly frustrated with what at first I thought was a failure to raise IGF level, but after researching it endlessly, and many self experiments I've come to the conclusion that it's simply way, way to complex to simply point at 1 thing and say that's the problem. I won't even begin to touch on the question of impurities in the generic gh that we're buying, and whether or not those impurities (dimmers?) are causing a lack of rise in IGF cuz that's a whole other can of worms