In men
hCG is used a fertility drug in men with existing hypogonadism who would be fertile except long term
testosterone treatment. At a recent conference it appeared that the international medical community is evenly split between either
clomid or
hCG. Basically doctor's choice and/or prescribing comfort.
In men without existing hypogonadism, just suppression through exogenous
testosterone -- you're right, the body's own LH will increase testosterone levels. Those levels increase rapidly when exogenous testosterone (or derivatives) are withdrawn. If the taper is slow enough, there is really no requirement for hCG. However, if the individual has been on
AAS for an extended period (years) the testes may require an additional push to begin functioning again. hCG certainly adds that extra kick. But if you're cycling like most people do, i.e. 12 weeks, It's not necessary.
Fraggle