Death, of the user or somebody else. They are unaware of what is doing. Some illegal drugs can cause you have to have "super strength", Hallucinations, the "muchies", and several other side effects.
Hope I was able to help. :)
Yes, there are many of these kind of procedures, and here are some examples, like deep palpation and percussion, examination of the ear-drum or inside the nose
Teen parenthood gives you more hormones than adult parenthood