Pretty much exactly where I am at 4iu. Considered increasing but frankly I’m happy with the results so far. Z 1.6 puts you in the top 5% of your peers in terms of IGF, and still well within safe physiologic range.
I’m also starting to think IGF-1 hyper response isn’t the blessing it appears to be, for long term use. All the benefits apart from anabolism are in GH not IGF, while almost all the serious risks that have to be managed are in IGF. It kind of sucks to only get 2iu in and hit a high IGF that puts you close to a Z score of 3, stopping you from safely increasing GH any further.