If the danger is too complicated for people to reasonably understand in the amount of time they ordinarily spend trying to understand it, you already have a bigger problem. If the danger isn't that complicated and can be easily explained, you don't actually have this problem.

Well what is reasonable for a $5 bottle of ibuprofen? How about:

"Misuse of this product is dangerous and may cause death. Advil is not responsible for damages caused by misuse. Read and follow instructions on back of bottle"

That's a bit wordy but it indicates who is responsible (you) and what the gravity of the situation is (possible death). With that established, it means the onus is on the user to do more reading.

IANAL but I would like to belive something like that would satisfy all parties.

I don't necessarily disagree, but the way you framed it is a little too close to "Please read our privacy policy for more information", which doesn't get us anywhere. It works for ibuprofen because those instructions on the back are really quite short, so expecting customers to read them is more than reasonable IMO.