Yes! I used it last year when my lad dropped weight and we couldn't figure out why. He had it to see if it helped before we resorted to blood tests. (these came back clear)
It did seem to make a difference - he perked up a bit when he was on it. But the problem he had would have counteracted some of the treatment anyway. I would recommend it, though.
You get it through Badminton Horse Feeds, http://www.badmintonfeeds.co.uk/
Look under Grazing and Remedial Supplements (Product Finder first)