I never leave reviews but, after our vet suggested we try this, I have been very impressed with the results (and Pacific Pet Supplies is the cheapest I have found it). We have a very timid and insecure border collie, made worse since she lost her companion dog. After just one day of starting her on Zylkene she casually sat herself down next to our cat, whom she is normally terrified of and avoids like the plague. I could hardly believe it! They will never be best friends but the fear element seems to be diminishing. Since then I am spotting slight changes in her behaviour and confidence, finding her doing things that she would normally be too anxious to do. I would definitely recommend giving Zylkene a go. I wish we had started our dog on it long ago.