"My kitty, 10 years old, was a little lethargic and after a few time of mixing this in his food he is noticeably more active. He is an indoor cat and loves to run back and forth from one end to the other in the house now. As this is a natural product and I myself take natural supplements I am happy that there is a product like this that is available for my precious cat. Although, as all cats can have a tendency to be finicky, I mix it in his wet food and he just eats it all up. Just wish it didn't have to be stored in the fridge, but I guess that ensures it is fresh after opening. You've gotta try it."