I'm certainly no scientist,...and far from one to-boot.
Still, I personally see no point for anybody marketting a cure for hangovers that already exists naturally.
Such being, in that if one perpetually stays drunk,...one will automatically never experience a hangover. He or she might not live very long, but such a fool will certainly remain hangover free.
So it is written,...and why some daily have what are called: "Early Morning Eye Openers", instead of vitamins
Neil