To understand why HCG can't be used in both cycle and pct, you first need to understand what role it plays in cycle and PCT.
HCG in cycle and PCT
When bodybuilders use high levels of AAS to build muscle, large amounts of exogenous AAS trick the brain into thinking that the body already has sufficient levels of testosterone to stop producing GnRH(gonadotropin-releasing hormone), Without GnRH, the pituitary gland stops releasing LH, and testosterone production is dependent on LH stimulation, so high levels of AAS shut down endogenous testosterone production.
HCG mimics the action of LH(lutein hormone) to promote the production and release of testosterone in the testicles. When use HCG in cycle, hcg helps maintain the ability of the testicles to produce testosterone during the cycle. When use HCG in pct, which is affected by androgen and estrogen levels in the body, LH is not immediately produced and it helps restart the testicles' ability to produce testosterone. Therefore, regardless of whether hcg is used for cycle or PCT, it replaces the role of LH, promotes the production and release of testosterone, and helps maintain endogenous testosterone levels.
What would happen if I continue using HCG in PCT after using in cycle?
The main purpose of PCT is to stimulate the testicles to produce testosterone and eliminate the possible side effects of estrogen, both of which can also be prevented during the cycle, the use of HCG during the cycle to maintain endogenous testosterone production, and the use of AI(aromatase inhibitors) to solve the possible effects of estrogen in advance. The separation of building muscle and solving side effects is called "cycle" and "post cycle" in order to separate goals from solving possible side effects of achieving goals. Focus on building muscle in cycle and solve side effects completely in post cycle. Producing while solving may affect the outcome of the cycle.
Therefore, the post cycle is to completely solve the side effects, because hcg is used in the cycle, if it is still used in the post cycle, it will affect the recovery of the HPTA axis, and the testosterone produced by the testis may not come from GNrH-LH-testosterone, but from the LH analog-testosterone. Therefore, if HCG is used in cycle, there is no need to use it in PCT.
HCG is precisely for PCT, and bodybuilders choose to use it in cycle for one of the most immediate reasons, to prevent testicular atrophy. Because if the cycle is too long, the production of endogenous testosterone is turned off for a long time, according to the principle of "use or lose", the testicles do not exercise the mission of producing testosterone for a long time, and will gradually degenerate and appear as "smaller". Therefore, it is necessary to maintain the function of the testicles during the cycle to ...

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