Name me please an international LEGAL drug that has the following effects....?

Question

it can make a person (about 17-20 years old) feel unconscious or asleep for about a day or two, has no side effects and isn't lethal, and as safe as possible.

Answer 1

Whilst this is often done in movies without any problems it is not the same in real life. This is just one of many Hollywood myths (or lies).

In the real world no drug has no side effect. Taking enough of any legal tranquilizer or other drug to knock you out will always involve serious (possibly delayed) side effects.

So what your asking cannot be done safely. Especially not by someone not trained as an anesthetist. Highly trained anesthetists can struggle even in operations only lasting a few minutes. Are you really medically trained enough to know what to do with an unconscious guy. For example if he swallows his tongue can you fix that because if not he will die.

Answer 2

If you are planning to do this to someone else, STOP THINKING ABOUT IT.

Would you want someone to do this to you?!