T4 levels

[Tldg45]

At what level does T4 convert to T3?

[shaws Administrator]

T4 should begin convert gradually from whatever dose you are taking but it takes about six weeks for it to build up in your system. Thereafter incremental doses of 25mct T4 about every six weeks should be prescribed till the patient feels much better. The doctor should not cease increasing just because the T4 is 'anywhere' within the range, nor if the TSH is low. The most important test, is not the TSH but Free T4 and Free T3 which they rarely do for some unknown reason to me, but I'm not medically qualified but I assume that's the instructions they are following from the the Associations.

[Clutter]

Tldg45,

I think that T4 is converted as and when the body requires more T3. I don't think T4 has to be at a certain level but obviously inadequate levels of T4 will mean there is little to convert.