HCG (Human chorionic gonadotropin) description
Human chorionic gonadotropin (hCG) is a hormone produced by the cells that surround a growing embryo. The pituitary analogue of hCG, known as luteinizing hormone (LH), is produced in the pituitary gland of men and women of all ages. It is a glycoprotein composed of 237 amino acids with a molecular mass of 36.7 kDa. As for endogenous forms of hCG, there are several ways to categorize and measure them, including total hCG, total hCG at the C-terminus of the peptide, intact hCG, free β-subunit of hCG, β-core fragment of hCG, hyperglycosylated hCG, nicknamed hCG, alpha hCG and pituitary hCG. As for pharmaceutical preparations of hCG from animal or synthetic sources, there are many gonadotropin preparations.
HCG function during pregnancy
Human chorionic gonadotropin (hCG) is sometimes called “the pregnancy hormone” because of its important role in maintaining pregnancy. Pregnancy tests check hCG levels in the urine or blood to determine if the test in positive or negative. HCG interacts with the LHCG receptor in the ovary and promotes the maintenance of the corpus luteum in early pregnancy. This allows the yellow body to secrete the hormone progesterone during the first trimester. Progesterone enriches the uterus with a thick lining of blood vessels and capillaries to keep the fetus growing. Due to its highly negative charge, hCG can repel the mother’s immune cells and protect the fetus during the first trimester. Several vaccines against human chorionic gonadotropin (hCG) to prevent pregnancy are currently in clinical trials also.
HCG and testosterone production
Due to its similarity to LH, hCG can also be used clinically to induce ovulation in the ovaries as well as testosterone production in the testes. Human chorionic gonadotropin also plays a role in cell differentiation / proliferation and may activate apoptosis. In men, HCG injections are used to stimulate Leydig cells to synthesize testosterone. Intratesticular testosterone is essential for spermatogenesis from sertoli cells.
Typical uses of HCG in men include hypogonadism and fertility treatment, including during testosterone replacement therapy to restore or maintain fertility and prevent testicular atrophy. In one study, men taking testosterone along with hCG were able to maintain adequate sperm production. In another study, men taking testosterone along with hCG were able to maintain testosterone production in the testicles.
In men, doctors prescribe hCG to combat the symptoms of hypogonadism, such as low testosterone and infertility. It can help the body increase production of testosterone and increase sperm production, which can reduce infertility. HCG can help increase testosterone levels, increase fertility, and increase gonad size. Injections of hCG are also sometimes used as an alternative to testosterone products in men with testosterone deficiency. Testosterone deficiency is defined as testosterone blood levels less than 300 nanograms per deciliter along with symptoms of low testosterone, including:
- low sex drive and libido
- depressed mood
HCG, bodybuilding and anabolic-androgenic steroids use
In the world of bodybuilding, HCG is often used in combination with various cycles of anabolic-androgenic steroids (AAS), such as post-cycle therapy (PCT). When exogenous anabolic-androgenic steroids is introduced into the male body, the natural loops with negative feedback cause the body to stop its own testosterone production by shutting down the hypothalamic-pituitary-gonadal (HPGA) axis. This causes, among other things, testicular atrophy. HCG is commonly used during and after steroid cycles to maintain and restore testicular size, as well as normal testosterone production.
High levels of anabolic-androgenic steroids, which mimic natural testosterone in the body, cause the hypothalamus to stop the production of gonadotropin-releasing hormone (GnRH) from the hypothalamus. Without GnRH, the pituitary gland ceases to release luteinizing hormone (LH). LH normally travels from the pituitary gland through the bloodstream to the testes, where it triggers the production and release of testosterone. Without LH, the testicles stopped producing testosterone.
In men, HCG helps restore and maintain testosterone production in the testes by mimicking LH and triggering testosterone production and release. However, if HCG is used for too long and at too high doses, the resulting increase in natural testosterone and estrogen would eventually inhibit endogenous luteinizing hormone production through negative feedback to the hypothalamus and pituitary gland.
HCG as a tumor marker
Human chorionic gonadotropin – HCG can also be used as a tumor marker because its β subunit is secreted by some cancers, including seminoma, choriocarcinoma, germ cell tumors, hydatidiform mole, choriocarcinoma teratoma, and islet cell tumor. For this reason, a testicular cancer test may be a positive result in men. The normal range for men is between 0-5 mIU / ml. In combination with alpha-fetoprotein, β-HCG is an excellent tumor marker for monitoring germ cell tumors.
HCG possible use and effects
- HCG helps restore and maintain testosterone production in men
- HCG can be used as excellent tumor marker for monitoring germ cell tumors
- HCG injection is extensively used during pregnancy for final maturation induction in lieu of luteinizing hormone (in the presence of one or more mature ovarian follicles, ovulation can be triggered by the administration of HCG)
HCG possible side effects
- gynecomastia (growth of male breasts)
- pain or/and swelling at the injection site
Uses of HCG for research can be very different. For Hypogonadism / testosterone production restoration usual (male) adult dose of HCG is 500-1000 IU 3 times a week for 3 weeks, then 500 to 1000 IU 2 times a week for 3 weeks, or 4000 IU 3 times a week for 6 to 9 months, then 2000 IU 3 times a week for 3 months.