My Storm was just diagnosed with hyperthyroidism and is on pills. I have to take him back to the vet next Sat. for a weight check and blood draw to test his thyroid level again. My vet did mention this treatment to me but she said that if a cat's kidneys aren't under control first that this treatment would kill them. Storm didn't do too well at first but now he's doing better. He does seem to be extremely hungry though and also very restless. I think he may need a higher doseage than he's receiving.