Are these so-called energy drinks any good? Do they do what it says on the tin, i.e. replace energy and prevent de-hydration? Or is it just theraputic whereby, if you think it's doing you some good, then it will?
It's a "placebo" effect, rather than therapeutic. The answer is that they do minimal good, and are a triumph of marketing - the art of selling people useless crap they don't need.