My 13 year old diabetic cat has been insulin dependent since last June.
I tried several well known prescription brands first including Hills Prescription and Royal Canin, but this food is by far the best at regulating my cat's diabetes (it has the highest protein/lowest carb % of all the brands I have purchased)
In addition, my cat prefers the taste of Purina compared to the others so it's win-win!
My cat, Small, is now in remission, so the insulin has been stopped.
Will use Purina indefinitely.