I think post workout is best! The way I did it was first take my GH right after workout(no drinks or food) wait 20 minute(gives the GH time to circulate) then i did Humalog along with a Carb drink with BCAA's and Glutamine added!
20-25 minutes later after my carb drink then I take my Protein drink!
I believe in splitting up my carbs and proteins by taking them separate after working out cuz this gives ur body the chance to fully concentrate on braking down a single nutrient at a time (which i think is more efficient) instead of taking them together!