The sanctuary where I volunteer has had very good results using Renavast on older cats with kidney disease. One guy, Billy, a very old cat that we all thought was heading into his last days, started Renavast and he started feeling a lot better. He went from we all thought he was dying, to running around chasing the other cats. His fur looked better, too. He stuck around with us for almost another year and a half. The ingredients are listed on the bottle. I definitely recommend it and would have your vet look into it further if you have questions.