Must it be drunk right away after mixing, or can I prepare it before a workout, refrigerate it, and drink it 1 hour later? Will it still be chemically active? I just want to be able to drink it right away coming home from the gym without delay.

It will be fine an hour later.

After all, milk (source of whey proteins) doesn't lose its protein when it sits in your fridge for a week.

you're good. those aminos aren't going anywhere. :tu:

Thanks guys, that's a real load off my mind. I just started on Whey protein today and I'm going to make it staple drink right after every workout.