My cat has a t4 level of 4.1. He has not had an actual diagnosis but a lot of symptoms. (hungry, hyper etc...) Since he is on the upper end of normal, can I start giving him something now to prevent the thyroid hormone from getting higher?

It would definitely be a good idea to get your kitty started on the Resthyro to help balance the thyroid before it becomes overactive. The Resthyro also helps with other symptoms of hyperthyroidism such as anxiety and cardiovascular support. You will still want to monitor your kitty’s T4 levels. Your vet may have recommended a repeat test in a few months to be sure the level doesn’t increase further.