Low T3 causes a whole host of testicular development and maintenance problems leading to germ cell issues and sex hormone secretion problems.
It also goes on to discuss how LH (and
HCG) both fail to work in situations with low T3 thyroid hormone. So this explains why a few guy's on this forum haven't had any luck with
HCG treatment restoring testicular size. And if my memory serves me right they all have thyroid problems (elevated TSH's above 2 - low free t3). This also explains why some guy's with high E2 have ED and libido issues due to low thyroid hormone.
I believe low T3 eventually leads to testicular malnutrition that can lead to atrophy and various other problems. This explains my own situation.
It also states impotence and loss of desire is linked with hypothyroidism. It's worth reading over for sure as it discuss more indepth the links with SHBG and thyroid.