I would hazard a guess and say 'goose-egg'. The biggest killer for bodybuilders seems to be diuretics like lasix. But I have yet to hear any doctor say the juice killed him. That only comes from newscasters who apparently know more than coroners about what kills people, and what doesn't.
Aspirin kills tons of people each year. And cars. Cars kill, especially if they are red and named Christine. And cats that you have brought back from the dead, they kill, too. Oh, and big dogs named Cujo, they kill.
Anything else?