Excerpt:
the Lille and Tehran findings may not be as welcome as one might imagine, because the hormone in question is Gonadotrophin Releasing Hormone (GnRH), which plays a defining role in the process of reproduction as well as a “non-reproductive” role in the process of brain development and maintenance of function. Its reproductive role is deliberately “blocked” by medical practitioners committed to hormonal “affirmation” of a confused child to a gender incongruent with biological sex. In the same process, however, its non-reproductive, neurological role is also interrupted.
The contradiction bears repeating. Researchers have found deficiency of GnRH in the brains of DS sufferers is associated with progressive cognitive decline, but the process may be “rescued” by its replacement. They point to a necessary neuro-modulatory role of GnRH in the development of the brains of men and mice.
Conversely, proponents of hormonal “affirmation” of a child (perhaps as young as nine) to a gender incongruent with chromosomes, deliberately administer compounds that “block” the production of GnRH (and, thus, puberty), in the claim that the process will provide more time for appropriate cognitive appraisal of identity, the process of puberty, the role of sex hormones, the implications of gender surgery, and the loss of sexuality including sensation and procreation.
Disregarding the question of whether any child possesses sufficient maturity of cognitive power to digest and responsibly act on such complicated, life-changing matters, even if cognition is not limited by drugs, it should not be forgotten that the brains of almost all gender-confused children are also burdened by associated neurodevelopmental challenges such as autism, and lasting traumas of social disruption.[3][4] [5][6]
Continuous administration of GnRH desensitizes the HPG axis by downregulation of GnRH receptors and desensitization of gonadotropes, following an initial stimulatory effect (39). <
And the answer is not to just replace/suppliment GnRH.
A feed back loop exist that will reduce sensitivity to the hormone.
Source
https://www.ncbi.nlm.nih.gov/books/NBK279070/