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.