Have several horses in my barn that have shown great improvements with it.
Several of those horses had noticeable weight and muscle gain, filling out properly, and another horse had developed a sweating disorder where he would not generate sweat, and now is on a platinum supplement for that, and is sweating normally.
I personally tried it on my Thoroughbred and found no noticeable changes, however I wasn't having any issues when I tried it, so it wasn't a very fair trial.
The company recommends giving a pack twice daily, however at our barn we only give it once daily and find that the results have been sufficient, and have cut the costs exponentially.