I make "no perfect market" or "perfect information" assumption.
I am pretty confident that people will take stupid risks, as I am confident that people who want to be safe - buying from reputable sources - will be able to.
How do people without a scientific background and without the access to clinical testing data (since we're deregulating here companies won't even have to do them before going to market legally) have a hope of evaluating what new drugs are safe and which companies are reliable?
If you want an example of how an unregulated medicine market works, check out the American medical "supplement" market. Plenty of producers, dubious and often purposely wrong claims, often don't even contain the compound as advertised, and still hilariously expensive.
If unregulation begets competition and that begets lower prices, why do these turmeric supplements cost $30[0] while you can go to the spice aisle and get 10x as much for $5?