Fair rebuttal, but is that far off from what they are currently doing even in a regulated industry? I know its not heroin but pain meds were previously handed out like candy and people became addicted to pain meds after receiving them legally through a doctor. Fortunately doctors are now more reluctant to hand out meds due to the liability. To directly answer your question, I think the end results would be the same if it was not regulated because a company has in their best interest to prove that their product is proven through extensive testing and safe for use, otherwise its a terrible product and people will not use it. The hospital/doctor doesn't want to give out shady drugs or they will have a reputation as a shady hospital/doctor.
In the case of an illegal/legal substances used as medical practice, I think a better example is THC. I'm no expert on the issue but am from Colorado where it has used commonly as a "medicine" to now being similar to smoking a cigarette. There are numerous cases of parents showing how THC has reduced severe cases of childhood seizures but there are also cases showing that THC used at a young age is detrimental to brain development. The government is allowing it to be used, but it could be damaging. I guess I am cautious to trust the governement to know what is best for me. They could say its good or bad and I would still be cautious.
Another case would be the "worlds best burger". How many food chains claim they are the best? Does the government need to determine what great burger is? The market, through restaurant ratings, yelp, word of mouth and popularity can actually prove that a restaurant has a good burger compared to a false claim.
That was a roundabout way of saying I understand your point. No regulation sounds awful because people can do stupid things and I am potentially naive in thinking that a market can regulate itself.