[Pigalowda]

Did you have hypogonadotropic hypogonadism from the brain injury? If you did the endocrinologist is right about the TRT. Without TRT you would have been infertile because you lacked GNRH/FSH/LH from disruption of your hypothalamic pituitary axis due to injury. Your Leydig cells would not be able to produce local testosterone in your testes for your Sartoli cells to utilize in spermatogenesis.

With TRT you would have systemic androgen but not high enough in your testes locally for spermatogenesis. So with or without TRT you would be infertile (if you have hypogonadotropic hypogonadism)

[Auracle]

It was never ruled one way or the other and the brain injury is just a theory based on the start of my symptoms (along with losing height after), but to quote him "if TRT worked to reduce sperm counts enough we'd be using it as birth control." He wasn't talking specifically about me.

From what I remember my FSH and LH were normal. I don't recall GNRH being tested.

[Pigalowda]

Usually with pituitary axis injuries the other hormones are affected as well and not just FSH/LH.

The FSH and LH being normal with low testosterone means there’s some kind of dysfunction. There’s an inverse relationship and if T is low LH should be higher to induce synthesis.

Sort of like in women’s menopause - when the ovaries run out of oocytes the ability to produce estrogen is gone and FSH/LH increase.

Anyways, obesity could be another issue. Adipose cells produce estrin and estrin has promiscuity with the estrogen receptor which reduces testosterone production. Another is elevated prolactin which has multiple causes and can reduce T production.

Anyways, my caffeine ranting is at an end. Good luck