Part 4/9:
One of the most startling revelations from Dr. Doyle was that TRT could be akin to "chemical castration." She detailed the biological mechanisms involved, especially how exogenous testosterone interferes with the brain's signaling pathways. Normally, the hypothalamus and pituitary gland regulate hormone production through a negative feedback loop:
The hypothalamus signals the pituitary.
The pituitary sends signals to the testes to produce testosterone.
When external testosterone is introduced, this loop is disrupted, often leading to decreased natural testosterone production.