This is why HCG is absolutely necessary.
HCG is to synthetic testosterone as Clomid and Nolvadex are to tribulus.
The action of HCG is identical to that of pituitary LH. This takes place independantly and is not affected by exogenous hormones and/or preexisting HPTA suppression. Therefore, it directly causes a dramatic increase in endogenous testosterone production. Obviously, the impact is strong enough considering HCG usage is commonly associated with the developement of gynecomastia.
Both Clomid and Nolvadex increase pituitary LH secretion in secondary manner by blocking estrogen negative feedback on the HPTA. This is not strong enough by itself to counteract the severe imbalance in the androgen:estrogen ratio that is encountered post cycle.
Regardless, endogenous LH secretion increases as the hormones diminish from your system. In conclusion, to avoid uneccesary delays in recovery, HCG is used to immediately increase endogenous testosterone production, testicular volume and spermatogenesis while Clomid and Nolvadex are used as anti estrogens and to increase pituitary LH secretion.
An almost bullet proof PCT protocol is 1000-1,500 IU's HCG 3x/wk (mon/wed/fri), 50 mgs Clomid ED and 20 mgs Nolvadex ED for the first three weeks followed by an additional 50mgs Clomid ED and 20 mgs Nolvadex ED for 2-3 weeks.
Both high levels of estrogen and/or prolactin as you begin PCT will complicate or delay recovery. This is not an issue as long as the usage of an aromatase inhibitor when using aromatizing AAS and an anti prolactin when using nandrolones are used to minimize of prevent the increase in excess circulating concentrations of these hormones.
Jenetic