For the bodybuilding community, the main purpose of its use is to maintain, increase or restore proper endogenous testosterone.
During PCT, HCG is best used in conjunction with other testosterone production stimulating compounds, and the practice of using HCG alone as the sole hormone restorer at the end of the cycle is an outdated, pre-1990 practice.
Since the use of anabolic steroids by bodybuilders in the 1960s, 1970s, and 1980s, the understanding of HCG and all other drugs has greatly improved.
In fact, from the 1960s through the mid-1980s, most anabolic steroid users didn’t even use any compounds for endogenous hormone restoration, and PCT didn’t even exist at the time.
When HCG use became more popular (around 1980), it was the only compound used.
Since then, medical and scientific understanding of these things has begun to grow exponentially, and there is no reason for any informed and properly educated individual to use HCG on their own to achieve PCT.