My cat was diagnosed with hyperthyroidism a year ago it was in the beginning stages and the doctor asked me to bring her back in six months and go from there. I took her in as advised for a weigh-in, she had lost a 1/2 a pound, she was also overactive, wide eyed, and her fur was beginning to look funny. The doctor said there are several things that could be done, one is a medication that she would be on for life, however the cats don't generally like it and they become basically walking zombies, not to mention the other side effects. I looked around for something natural, and came across this along with a liquid formula from another brand which is normally a good brand as well but decided to give the granules a try. The instructions are crazy though, I decided to melt the granules in a drop of water and add that to her food and she eats it fine. It's only been a couple of weeks, but she eats a lot better, sleeps better, she's not wide eyed nor zooming around. She's like her self again. I highly recommend this to anyone with a hyperthyroid kitty.