does the shake have barleygrass, (or "barley green") or the grain? Wheatgrass is going to be really similar to barley green.
I bet there's nothing wrong with it. But I don't encourage having too high hopes for it solving anything, either.
In my young and susceptible to new age enthusiasms days... I had wheat grass at a juice bar most every day for something like a month, followed by some carrot-whatever juice concoction. I can't say I noticed any difference from the wheatgrass. Or noticed any difference when I dropped it. But I was just a wide-eyed health-food freak at the time, not in the least athletic....
And that should be worth about as much as the next bit of anecdotal evidence.
Wheat grass tastes pretty bad. Other than that it's like any other green supplement. Barley grass, in my experience, tastes vastly better (if im thinking of the right stuff).