How do we find laws regarding this? I want to study biochem and the effects of ingested/inhaled/injected substances on the brain. Maybe psychiatry would be good to learn about that too.
Anyway, once I had that, I'd be able to run tests in labs and stuff right? I assume that scientists get waved for scientific merit if conducting controlled trials, so we can learn about them and contribute to the world without becoming criminals.
As for legal substances, what troubles do they come across?