Madhacker,
I use either a 50 unit or 100 unit slin pin. When i mix the bac water/or sterile water I use the 100 unit pin. And pull back the full 100 units, then I mix it into the powder vial. Once its mixed with the GH powder it will equal 10 ius of GH.
So if you continue to use the 100 unit pin to give the injection and you want 2 ius, you would pull back to 20 units. Same on the 50 unit pin, you would pull back to 20 units. If you want 3 ius pull back to 30, 4 ius to 40, and so on.
This is if you use 100 units (10ius) to dilute the powder.