Do a little research on:
Ashwagandha - apparently raises T4 levels
In conjunction with:
Olive leaf extract - apparently increases the conversion of T4 to T3.
Iodine is an element that is needed for the production of thyroid hormone. Since the body does not make iodine, so it is an essential part of your diet. If you do not have enough iodine in your body, you cannot make enough thyroid hormone. Thus, iodine deficiency can lead to enlargement of the thyroid and hypothyroidism.