Blood test for what? I'm assuming that you're asking this question because the "blood test" is going to test for triglyc. and possibly cholesterol?
If that's the case, I believe you should be in a fasted state and the nurse would/should have told you this. My last blood panel required that I fast for at least 10 hrs.
Muslce Milk has quite a bit of fat and cholesterol in it the last time I checked.