I've heard of it but just never looked into it. Some of them make people think that there dogs are all of a sudden going to get jacked by being on them and I just don't buy into it. That's all genetics, diet, and exercise. Just google it and you can read about it
EDIT! okay so it peaked my interest and its a vitamin supplement not claiming to get your dog jacked. My bad.....when people mention these things I think of bullymax supplements which has this big hulk looking bully in the advertising. Anyways, I also supplement with a good quality vitamin because during the extrusion processing of dog kibble alot of vital nutrients are lost so I'm all for a vitamin supplement. However there stuff is way over priced. I buy from onlynaturalpet.com and pay $40 for a big thing of vitamins that last months.