My old thread has more detail, but here's the Cole's Notes version: I appear to have a dysfunctional hypothalamus. Thyroid functions fine when stimulated, as do testes, and MRI is negative. This condition is causing clear hypogonadism, which I am currently on testosterone for, and a thyroid profile as follows.
Free T3: 2.9 pmol/L (2.6-5.7)
Free T4: 10 pmol/L (9-19)
TSH: 0.64 mIU/L (0.35-4.94)
Does this warrant thyroid replacement?