Human Chorionic Gonadotropin (HCG), a polypeptide hormone produced by the human placenta, is composed of an alpha and a beta sub-unit.
Chorionic gonadotropin for injection, is a highly purified pyrogen-free preparation obtained from the urine of pregnant females. It is standardized by a biological assay procedure. It is available for intramuscular injection.
The action of is virtually identical to that of pituitary LH, although HCG appears to have a small degree of FSH activity as well. It stimulates production of gonadal steroid hormones by stimulating the interstitial cells (Leydig cells) of the testis to produce androgens and the corpus luteum of the ovary to produce progesterone. Androgen stimulation in the male leads to the development of secondary sex characteristics and may stimulate testicular descent when no anatomical impediment to descent is present. This descent is usually reversible when HCG is discontinued.
Among athletes, HCG is used to stimulate natural testosterone production during or after a steroid cycle which has caused natural levels to be reduced. Stopping a steroid cycle abruptly, especially when endogenous androgens are absent, can cause a rapid loss in the athlete’s newly acquired muscle. When HCG is used to stimulate natural production, a notably pronounced crash may be avoided. Pregnyl HCG is always packaged in 2 different vials,one with a powder and the other with a sterile solvent. These vials need to be mixed before injecting, and refrigerated should any be left for later use.