Prescription replacement thyroid hormones come in two forms. One form are the "T4 group" (named because they contain four iodine atoms) and the other is the "T3 group" (with three iodine atoms).

The T3 group are more potent than the T4 group. If you have been prescribed a T4, you could discuss the option of a T3 group medication with your endocrinologist.

Also, production of hormones by the thyroid gland is controlled by a hormone called Thyroid Stimulating Hormone (TSH) which is made by the pituitary gland.

If it has not yet happened, you could ask your endocrinologist to arrange for a measurement of your blood TSH level - if it is abnormal that might indicate an issue with your pituitary gland.