Updated November 3, 2022
This information is for educational purposes only, to enable you to have a quality conversation with your doctor who is prescribing tests and medications. Several additional considerations are required to apply this panel for an individual.
The basic ideas are:
- TSH is a measure of pituitary function, not thyroid function. Therefore TSH is not utilized to assess the body’s (“peripheral”) need for thyroid hormone.
- If only T4 is adjusted, there are only three possible changes, up, or none. If T3 and T4 can be adjusted, there are nine possible changes.
- By measuring just three parameters, Free T4, Free T3 and Reverse T3, each with high, low, or “optimal”, there are 27 possible scenarios.
Proof of Components
rT3 blocks production of T3
Cortisol diverts T4 to rT3 rather than T3
TSH measures pituitary, not thyroid function
Thyroid Hormone is Consumed by Immune Cells During Infection
Which means that the hypothalamus and pituitary (which determine TSH level) may not respond properly during certain types of infections and deficiencies (for more click here).
Articles Supporting the Need/Benefit of T3
For more information about the benefits and indications for T3, see Combined Thyroid T4-T3 Therapy