Is it possible to develop an immunity to tylenol in a human lifetime

Searching ''tylenol tolerance I found that it is possible. Sorry, do not know how to compute the probablity. First reference lists a number of factors that must be considered.

You can destroy your liver and/or kidneys by taking too much over a few days or taking it for a long period of time.

Try accupunture instead :)

The only form of immunity that exists is allergy, and it is vanishingly rare. If you're asking instead about tolerance, that has nothing to do with the immune system. Tolerance does not seem to happen, either.

If you mean tolerance,
Yes you can. If you drink
more than 8 to 10 daily.

Your body gets saturated
by the excess of acetaminofen
in your body and the tylenol wont do
no effect on you

Maybe not an immunity but the body will get used to it if it is used often and you will need to take more (Which could be a bad thing). If you believe this is happening to you maybe you should try another painkiller or try taking a break from it until your body reacts normally to it is usage.