@leanguy 103 wrote:

I’ve read that HCG is similar to TSH in the body. Is it true that HCG can improve thyroid function?

HCG (chorionic gonadotropin) can potentially affect thyroid hormone activity.

1. HCG can act like TSH (thyroid stimulating hormone), increasing thyroid hormone production from the pituitary. In pregnant women, HCG levels are high enough to raise thyroid hormone by up to 50% over the non-pregnant state. In testosterone replacement therapy, the amount of HCG used may not be enough to significantly increase thyroid hormone production directly since small doses are used.

2. HCG can act like LH (Luteinizing hormone), stimulating testosterone production from the testes, when used in hormone replacement therapy. It will also stimulate TRH (thyroid releasing hormone) production from the testes. This would in turn increase TSH then thyroid hormone production from the pituitary.

HCG, however, also stimulates the production of aromatase enzyme from the testes. This will increase conversion of testosterone to estradiol. Estradiol, in turn, would increase thyroid binding globulin from the liver. This would reduce free thyroid hormone levels, reducing thyroid hormone signaling activity.

The sum of these actions would determine whether or not HCG would improve thyroid hormone signaling activity.