This is cool. One important note, HCG also suppresses the HPTA. It is an LH analog, bypassing the HPTA entirely. It stimulates the testes directly. HCG while on TRT or on cycle can prevent testicular atrophy as well as keep Leydig and Sertoli cells from going dormant. Additionally, HCG acts upon the CNS, helping to stimulate LH receptors in the brain, provides add affective enhancements in many on TRT, and assists in normalizing cognitive function that exogenous testosterone can disrupt.