I used to take a medicine for the flu that had a lot of caffeine. In fact I felt pretty energized after taking it, but I never knew why. So the question is, do we know what's in the drugs we take and what exactly are those components for? Is that important to you?
Our Creator supplied us with a perfect immunity system. Of course, that "perfect" is NOT 'perfect' to US---it's more 'perfect' the way a forge is 'perfect' for forging a weapon than it is the way 'a warm bath' is for 'soothing aching muscles.' In order to get through 'the forge' with minimal pain, we use "the drugs" (i.e. mostly to stimulate our immune-systems to "the right action" while deadening our senses to "the pains of those actions"). Which is to say: No, we don't pay much attention to what kinds of rat-poison is put into our medicine because we only care whether-or-not the medicine does what it says it'll do (and the exact side-effects are different for every person at different times ... e.g. I drink four cups of coffee a day (maybe that seems like a lot, but many people drink more), which would make some people (including me, after a week-or-two WITHOUT coffee) bounce off the walls).