T4 Free (FT4)
Most of the T4 in your body is bonded to protein, and a smaller portion (free) has not. This is why there is a free T4 test and a total T4 test. A free T4 test is usually preferred because from this test you can see how much is available for the body to use. This test can be ordered if a TSH has come back abnormal. Pregnancy can also affect your T4 levels.
$39.00Price for members $19.50
Preparation: Please do not exercise prior to testing. It is best that your blood is taken in a rested state.