Exogenous GH is going to work, reardless of taking carbs or not, but If fat loss is your main goal, a great decisson to make is to do AM fasted cardio and to take GH at that time. You can take GH at any point of the day though and it will still help with fat loss. If you only take GH in the morning, there would be less of a chance that it would effect your system hours later, when you would normally release your own GH. If you are injecting GH though, releasing your own or not, isn't really going to be an issue. I personally split my growth up through the day, taking no more than 4iu at a time. In one period that I came off, I had igf levels tested and it came back normal, so at least for me, I don't think I have a problem producing once I come off. I don't expect that I am producing much while I am using though.