hCG = human chorionic gonadotropin - a hormone that is most commonly linked with pregnancy in females. hCG levels in a pregnant female are drastically higher than a non-pregnant female. The elevated levels of hCG supplement the natural LH levels in the body produced by the pituitary gland. LH-like compounds (LH and hCG) are necessary to prevent the breakdown of the fetus and uterine lining during pregnancy. Increasing the LH levels in the male causes the testes to make their own testosterone. When using AAS the male body shuts down the production of GnRH (gonadotropin-releasing hormone) which tells the pituitary to make LH. Thus, hCH mimics LH and your testes produce testosterone. Long-term use of hCG, however, causes the body to indefinitely shutdown LH and thus hCG needs to be used for short periods of time and at the RIGHT time during PCT to get the boys back in the game. An endocrinologist, Dr. Simeons', theorized that the hCG also programmed the hypothalamus to catabolize adipose fat tissue only and not break down lean tissue to protect the fetus in pregnant women. He tested his theory by putting obese men on low doses of hCG and a 500 calorie/day diet. The results were incredible. However, it is important to note the hCG does NOT induce ANY fat loss. Rather the hCG spares the muscle tissue during catabolism. So you go catabolic (which is simply the breakdown of complex molecules into simpler ones) but you don't break down muscle.
hGH = human growth hormone - This protein-based hormone has been cited to increase height and bone growth in children and adolescents as well as have an anabolic effect on the muscles. The protein interacts with a receptor on the surface of cells and tells the cell to divide and multiply. The rapid multiplication of cells is what induces the growth. GH also stimulates IGF-1 (insulin growth factor 1). IGF-1 has a growth-stimulating effect on a number of different tissue types. Excess GH can cause pituitary tumors.