GH isn't going to be a great muscle builder on its own, so don't expect a ton. Adding a couple more IU would incresase the effect to some degree. Still, don't expect to gain 10 lbs in a year, running peptides alone, with no anabolics. It will however, possibly help with injuries and injury prevention. You may have also noticed a few lbs of water gain. This isn't going to hurt either, as long as it isn't so much that it slows you down. And GH will also keep you leaner, allowing you to eat more, if you want to gain muscle. It'll be less likely to turn into fat. 

So, if you are using 2iu now, start by increasing to 3iu. Then, in a couple wks, 3.5iu, then in a couple wks, 4iu. Take your time increasing the dose.

If you wanted to take it further, IGF-LR3 at 30mcg, taken right before your workout will help even more with muscule gain, taken on weight training days