I was tested for my thyroid a few months ago. My T4 and T3 came back normal but I was feeling better then. I haven't taken any thyroid medications but you should look into Armour Thyroid
It has both T3 and T4. You can take all the T4 you want but if the liver doesn't convert it to T3, it's water in your veins. If your doc will test you, have them check your levels of T4 and T3, this will give you a good indication as to what you need.
In any case, cleansing the liver is vital for the thyroid as well as so many other hormonal functions.