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Dear sir, what is difference between free T4 and free T3 (liothyronine) and their functions?

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Dr. Michael Kleerekoper
Internal Medicine - Endocrinology

In brief: T4 and T3 (liothyronine)

The pituitary in your brain controls T4 and T3 (liothyronine).
T4 is more abundant but T3 (liothyronine) is more effective. T4 converts quickly to T3 (liothyronine) Treatment with T4 tablets works well because it is ultimately converted to T3 (liothyronine). Please go online to an imaging program - I use Yahoo but others are available.. Look for "Thyroid images" !

In brief: T4 and T3 (liothyronine)

The pituitary in your brain controls T4 and T3 (liothyronine).
T4 is more abundant but T3 (liothyronine) is more effective. T4 converts quickly to T3 (liothyronine) Treatment with T4 tablets works well because it is ultimately converted to T3 (liothyronine). Please go online to an imaging program - I use Yahoo but others are available.. Look for "Thyroid images" !
Dr. Michael Kleerekoper
Dr. Michael Kleerekoper
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