We have two labs, a 14 year old chocolate and a 6 year old yellow. Our 14 year old is having some serious issues with his joints, coat and nails are very brittle (which is why I looked into collagen in the first place because I heard it was good for those things.) I got this one because it had added MSM for joints and biotin also. Both dogs go crazy for the flavor of it and I have seen noticeable improvements, particularly in our older boy. His nails especially are much stronger, his hair doesn’t seem to be falling out nearly as much, and he is moving around easier! I could hardly believe it honestly. I already bought another bottle! Thank you so much for such a great product. I’m glad we found it for our older dog’s golden time with us and grateful we’ll be able to catch these things sooner for our younger one and hopefully he never has those issues to start with !