off hand I don't know the exact effects it has on your gh/Igf-1/test levels etc.. but I do know that if your trying to get lean it will severely hinder your metabolism, I do believe it has negative effects on all the above especially test levels.
also its going to affect your training and for most people your sleep and your diet, and all of those are going to affect your Igf levels...
IMHO I think if your serious about training and you have goals you are trying to reach that drinking every week is a bad Idea.