but there are an incredible amount of different substances available. you could focus on one or 2 drugs at a time, and start using a new one whenever the tolerance is completely built up. you'll have stuff to do your entire life lol.
It's not really a matter of building up a tolerance. If you do enough drugs, it destroys your liver and nothing makes you feel good. Thankfully, the liver is the one organ in the body that can repair itself.