What factors determine the effect an energy drink will have on you?

Question

Like metabolism, weight, current energy level before drinking...

and I mean a Red Bull

Answer 1

The major one with Red Bull is to look at your caffeine intake, if there's a lot of caffeine in what you drink i.e you drink tea and coffee regularly then Red Bull will have little to no effect. If your energy levels are low you have more chance of noticing a difference too. Red Bull has never had any effect on me.