I love the digestive enahncer from Nature's Farmacy. My dogs did really well on it and it lasted quite a while. It's supposedly micro-encapsulated for a longer shelf-life which is why it doesn't have to be refrigerated. I've also had mine on ShowStopper (Animal Naturals) It does ok. I buy it because it seemed like "the most bang for your buck" since it's a joint/coat/digestive system/etc supplement. I might switch back to using a couple different supplements though. I really liked the Nature's Farmacy products.