Dude, in this regard I am "more libertarian" than most libertarians I know.
I do support the individual's liberty to ingest any substance they want and I also support any business owner's liberty to hire or refuse to hire or terminate any employee they want to for any reason.
If a business owner does not want someone working for them who uses drugs or alcohol (even on their free time) that business owner's rights to associate with whom they wish and not have to enter into a business contract with anyone for any reason is just as important as the other individual's right to use substances.
There has to be a balance in liberty for the employee and employer. If a person can use substances and still be a productive employee, they should find an employer who is alright with entering into a contract with them. Otherwise they should drink lots of water and use detox shampoo.
