Been using this product for sometime.

I have used Aminivast for years for both of my little Morkies.
It is hard to say b/c when you have been using a product such as this, well for a long time, I am not sure what their kidney values would had been without it. Personally, I believe it has helped them maintain a within range value for a long time before one of my babies developed Congestive Heart Failure which caused her kidney values to climb until she passed away.
I still use it on the other one and she has continued to maintain normal kidney values even with taking medication that effects the kidneys. So yes, I would recommended this product.