I'm not sure I understand what you're trying to say. Is it your contention that, if anyone could get opiates without any regulation or prescription, fewer people would take them than they do now? Why would scrutiny of any kind by anyone lead to reduced usage in a case like this if that scrutiny had no regulatory effect on who could obtain narcotic painkillers?

I understand (though disagree with) the libertarian philosophy that you should be free to take anything you please, but I fail to see how such a situation would lead to decreased use.