Unfortunately not. The standard blood tests for assessing thyroid function, only show how much hormone we have in the blood, not how well they are working. You may have adequate levels of thyroid hormones in your blood, but if they aren’t properly working, it won’t matter! Additionally, around 75% of thyroid hormone is stored in the muscle and brain tissue, NOT in the blood, so it can be difficult to see the whole picture when assessing the blood. An example of two of the many functional tests we run would be iodine and Reverse T3. If you have a deficiency of iodine, you will be unable to make thyroid hormone and if you have a high Reverse T3, your thyroid hormone will not be able to work, even if your thyroid hormone levels are good. It requires a deeper understanding of the contributing factors to thyroid health and the full picture of functional tests required to get a true picture of how your thyroid hormones are actually working.