[aenario]

I'd like to sell you some cough medication, it's all natural, made from a concentrate of two south-american plant called "coca" and "tabaco", everyone who tries keep asking for more, even when we increased the price !

Too bad the big bad governement regulation prevent me from selling it. It's absolutely ridiculous, all my customers wants it and I pay my taxes.

[Hitton]

I'm not a hard core libertarian to argue about whether banning drugs is good, but even in your scenario customers having information about what is the "medication" made of and any addictive properties those things might have would go a long way. And lets not pretend that whether a drug is legal (alcohol, tobacco, even marijuana somewhere) or not is result of rational process and not just result of lobbying and historical custom.