Quackery
Deliberate misrepresentation of the ability of a substance or device for the prevention or treatment of disease.
We may think that the day of patent medicines is gone but look around you and you will see them still.
They appeal to our desire to believe that every disease is curable or at least treatable.
Quackery also applies to persons who pretend to be able to diagnose or heal people but are unqualified and incompetent