i have always been told to use Test with the GH. I prefer to use Tren along with the Test.
They say that GH increases the number of muscle cells in the body, while Tren will increase the size. With this in mind, you can see that it would be ideal to use Test to help fill those new and increased size muscle cells. Not sure what your goals are, but i know some that will also add T3 and Slin to the cycle.
I have never used Slin, because i am a wimp, but using T3 with it will help you to reduce BF% while increasing Lean Body mass.
Someone correct me if any of this is wrong !