It's strange I bumped up to 4ius and now I sleep good but not great. What was the difference you saw from 4ius to 6?
I might not be the best one to answer this because i wasnt for so long on GH. However for me it was something like this:
Up to 2IU i had great sleep. With 4IU my sleep got worse. I also got some bloating so i started splitting it.
However later, i took 6IU right before bed and my sleep was good. Could be that i got simply used to it though. But many people get worse sleep with higer IU dosages right before bed.
I even have a friens who had bad sleep on 3IUs but great sleep on 6IU.
So i would say try it. Try higher dosages before bed. See if you get used to it. If not then aplit it up. After aplitting it up some time you could try it again. Or you could move your dosage completely and just take it in the morning.
Generally speaking, splitting your dosage up, will be better for fatloss. But one big GH dosage will (in my opinion) result in higher Ig-1 levels whivh is beneficial for anabolism (other would argue that tge high igf-1 levels in acromegalia come from a constant elevated GH levels and both are right)
In my humble opinion if you want to max. igf-1 dont split your dosage as long as you are under 6IU. With the logic behind it that: higher GH levels= higher igf-1 and 1-2 IUs ate considered a replacement level (not really but lets gow with this) so for your body to produce significant more igf-1 than normal you want significant higher GH levels than normal.
However if you take lets say 8IU you could argue that 4 IU is significant more than your natural GH level and its better two have 2x per day a igf-1 releasing impulse.
There is some literature who claims that more than 6IU (taken once) wont raise igf-1 further. (first of all they are taling about andocrine igf-1 which doesnt mean autocrine igf-1 wont continue to raise and therefore resulting in more anabolism but thats a different topic) But based on this you coukd argue, if you take 12 IU it would absolutely be better to split it up in two dosage.
Now other woukd argue against it and mengion a negative feedback loop and say you want a as high as possible GH dosage at once to override this.