That is the road to hell right there. Libertarians never recognize the harm caused because it usually happens much later, like the bullet that kills a man forty years after it hits him. Libertarians never see a proximate cause because the consequences are generally distant in time from the initiating event.
Introducing someone to drugs *IS* harming them, or is at least close enough to be regarded as reckless endangerment. Some people can try drugs and do not get addicted, others do. It is, in fact, a genetic crap shoot as to whether any given person will be swallowed up by a drug when others will reject it.
....And WHY is it a problem of YOURS?
As long as you aren’t doing it, just leave other people alone, and don’t use politicians to force your will upon others at gunpoint. I don’t.
I don’t concern myself with what other people do with their personal lives, as long as it doesn’t affect me or my family. Sure people do things I don’t like, but I don’t care.
Not genetic crap shoot... spiritually determined.