Description
Human Chorionic Gonadotropin (HCG) was first developed to induce ovulation in females as it mimics the hormone luteinizing hormone (LH) in both females and males. It’s used by body builders and steroid users also because of this action where it can maintain testicular size and function in steroid users offering an advantage to those wishing to one day come off of steroids and recover. It will boost endogenous testosterone via direct stimulation and also sperm count by stimulating the leydig, germ and sterol cells. HCG can be used during the steroid cycle or in post cycle therapy (PCT) when the testes have atrophied and need to be directly stimulated. Each HCG vial contains 5000iu
Human chorionic gonadotropin interacts with the LHCG receptor of the blastocyst and promotes the maintenance of the corpus luteum during the beginning of pregnancy. This allows the corpus luteum to secrete the hormone progesterone during the first trimester. Progesterone enriches the uterus with a thick lining of blood vessels and capillaries so that it can sustain the growing fetus. Due to its highly negative charge, hCG may repel the immune cells of the mother, protecting the fetus during the first trimester. It has also been hypothesized that hCG may be a placental link for the development of local maternal immunotolerance. For example, hCG-treated endometrial cells induce an increase in T cell apoptosis (dissolution of T cells). These results suggest that hCG may be a link in the development of peritrophoblastic immune tolerance, and may facilitate the trophoblast invasion, which is known to expedite fetal development in the endometrium. It has also been suggested that hCG levels are linked to the severity of morning sickness in pregnant women.
Because of its similarity to LH, hCG can also be used clinically to induce ovulation in the ovaries as well as testosterone production in the testes. As the most abundant biological source is women who are presently pregnant, some organizations collect urine from pregnant women to extract hCG for use in fertility treatment.
Human chorionic gonadotropin also plays a role in cellular differentiation/proliferation and may activate apoptosis.
What is human chorionic gonadotrophin?
Human chorionic gonadotrophin is a hormone produced by the cells that surround the growing human embryo; these cells are called trophoblast cells and will eventually go on to form the placenta. Human chorionic gonadotrophin can be detected in the urine from 7-9 days post-fertilisation as the embryo attaches and implants in the womb; it forms the basis of most over-the-counter and hospital pregnancy tests.
During the menstrual cycle, when an egg is released from the ovary at ovulation, the remnants of the ovarian follicle (which enclosed the egg) form a new, temporary ovarian gland called the corpus luteum, which produces the hormone progesterone. If, after two weeks, the ovulated egg remains unfertilised, the corpus luteum stops producing progesterone. Through a feedback mechanism, this signals the pituitary gland to produce follicle stimulating hormone (and to a lesser extent luteinising hormone) to initiate the next menstrual cycle. However, in the event that the ovulated egg is fertilised by sperm and an embryo is conceived, it is vital that the corpus luteum continues to produce progesterone until the placenta is established (the placenta then takes over progesterone production). Human chorionic gonadotrophin is the embryonic hormone which ensures the corpus luteum continues to produce progesterone throughout the first trimester of pregnancy.
As well as maintaining progesterone production from the ovary, human chorionic gonadotrophin may also play a role in making sure the lining of the uterus (endometrium) is ready to receive the implanting embryo. Recent studies have indicated that human chorionic gonadotrophin may help to increase the blood supply to the uterus and be involved in re-shaping the lining of the uterus in preparation for the implanting embryo.
How is human chorionic gonadotrophin controlled?
Human chorionic gonadotrophin is produced by the trophoblast cells which surround the developing embryo at approximately day five of pregnancy. The amount of human chorionic gonadotrophin in the bloodstream doubles every 2-3 days as development of the embryo and placenta continue, and levels peak at around six weeks of pregnancy. Following this peak, levels of human chorionic gonadotrophin fall (although they remain detectable throughout pregnancy). Once the placenta is established, it becomes the main source of progesterone production (around week 12 of pregnancy), and human chorionic gonadotrophin is no longer required to maintain ovarian function. However, human chorionic gonadotrophin may have additional beneficial effects in the latter stages of pregnancy; such roles are currently being investigated by researchers.
What happens if I have too much human chorionic gonadotrophin?
There is no strong evidence that high levels of human chorionic gonadotrophin cause direct negative consequences. Very high levels of human chorionic gonadotrophin are rare but can indicate hyper-proliferation of the placenta (also referred to as hydatidiform moles or molar pregnancies) which can lead to cancer (choriocarcinomas) in some cases. Levels of human chorionic gonadotrophin may also be elevated sometimes in association with some non-pregnancy related cancers (eg kidney, breast, lung and gastrointestinal tract). In such cases, levels of human chorionic gonadotrophin in the blood/urine can serve as a tumour marker.
In pregnancy, a link between high levels of human chorionic gonadotrophin and occurrence of Down’s syndrome has also been suggested. Studies have shown that the levels of human chorionic gonadotrophin in a Down’s syndrome pregnancy are approximately twice that of an unaffected pregnancy. However, this is a correlation and does not mean that high levels of human chorionic gonadotrophin cause Down’s syndrome; further research is needed to investigate this link.
What happens if I have too little human chorionic gonadotrophin?
Low levels of human chorionic gonadotrophin can indicate a failing pregnancy. Reduced levels of human chorionic gonadotrophin are often observed in ectopic pregnancies (where the embryo implants outside of the uterus) or in miscarriages.
