(human chorionic gonadotropin)
Scientists first recognized a specific hormone now called Human Chorionic Gonadotropin (HCG) in the 1920´s (1). HCG is no doubt one of the most misused, misunderstood and underutilized tools in bodybuilding pharmacology we have available. HCG is not a steroid, but a naturally occurring peptide hormone, produced by the embryo in the early stages of pregnancy and later by the trophoblast (part of the placenta) to help control a pregnant woman´s hormones (1). This makes the uterine lining ready for implantation of the fertilized egg. HCG is a glycoprotein composed of 237 amino acids and has a mass of 36.7kDa. HCG basically "acts" as Leutenizing Hormone (LH) in your body. LH is a Gonadotropin. They were first extracted from the human in 1958; more precisely the pituitary glands. A gonadotropin is any substance that stimulates the gonads (ovary, testes). It is heterodimeric (initiates prophase of mitosis) with an alpha subunit identical to LH (luteinizing hormone), FSH (follicle stimulating hormone) and TSH (thyroid stimulating hormone). LH is as stated above is called a gonadotropin because it stimulates the gonads (testes). It is produced in the pituitary cells and is made up of a beta chain of 115 amino acids and an alpha chain of 89 amino acids. In the testes, the LH binds to receptors on the leydig cells which in turn stimulate the synthesis and secretion of testosterone. Like LH, FSH is also called a gonadotropin. It consists of a beta chain of 115 amino acids and an alpha chain of 89 amino acids, the same as LH. Production and release of FSH is controlled by GnRH (gonadotropin releasing hormone). FSH stimulates testicular growth and supports the function of sertoli cells, which are needed for sustaining maturing sperm cells. TSH is also known as a thyrotropin and is secreted by cells in the anterior pituitary glands. TSH is comprised of a beta chain of 112 amino acids and an alpha chain of 89 amino acids. The alpha chain is the same as that found in the two other pituitary hormones, LH and FSH, and HCG as well. TSH is produced when the hypothalamus releases TRH (thyrotropin releasing hormone). TRH then causes the pituitary gland to release.
TSH. TSH makes the thyroid gland produce triiodothyronin (T3) and thyroxine (T4), which controls the body´s metabolism.
HCG LEVELS & Pregnancy
HCG is clinically used to induce ovulation and treat ovarian disorders in women, as well stimulate the testes hypogonadal (underproduction of testosterone) men. It is also used in the treatment of undescended testicles in young males. HCG offers no potential performance enhancement in female athletes, but does prove to be very useful in male athletes especially those that use AAS. As stated above HCG in males is similar to LH, because they are similar and LH binds to receptors on leydig cells stimulating synthesis and secretion of testosterone, the use of HCG would be an added bonus to ASS users even if there is a lack of endogenous LH. Since HCG increases the body´s natural testosterone levels its use during long or extremely high dosed cycles can be most beneficial were the effects on the hypothalamus causes a depressed signal to the testicles. The result of the depressed signal leads to what is known as testicular atrophy (shrunken nuts). The use of HCG will send an artificial signal to the testes (again, as if it were actually LH), thus preventing (to some degree) atrophy. It not only helps to maintain testicular size and condition but it will also help in restoring testicles back to their original size. At a time when below normal androgen levels (due to ASS use) could become costly. Restarting natural testosterone production as quickly as possible is of a special concern in males at the end of a cycle of AAS. The price paid by bodybuilders for failing to raise natural test levels is the loss of most if not all the hard earned muscle you have gained, the main cause is cortisol. Cortisol sends a message to the muscles that is opposite to that of testosterone. If cortisol is not dealt with (because of an extremely low testosterone level) it will quickly strip away the new and hard earned muscle you have just gotten.
Some users find that they have better gains and quicker recovery while using HCG during a cycle of AAS. This first claim is more than likely due to the fact that the body has a high level of natural testosterone as well as that provided by the use of AAS, and the second may be somewhat justifiable, as stimulating the testes to secrete testosterone intermittently may aid recovery. Perhaps this is due to the maintenence of a higher level of Inter-Testicular-Testosterone (ITT) provided by the intermittent use of HCG, which should greatly aid recovery of the hypothalamic-testicular-pituitary-axis. An average dose of HCG during a cycle is between 500iu to 1000iu every week to every other week while on a cycle. In one study I looked at, a single injection of 6000IU of HCG elevated test levels for 6 days. That´s why a lot of people recommend taking it every 3-5 days. We´d have more stable blood levels, though if we shot it more frequently. Remember, it´s non-estrified and a water-based injectable, after all. In that same study I just spoke of, 1500IU of HCG shot test levels up between 250 and 300%. Taking it all at once however will cause an increase in estrogen levels caused by the aromatization of normal testosterone; the result may be a case of gynecomastia for the user (3).
As regards HCG´s use of Post-Cycle-Therapy (PCT), smaller and more frequent doses after a cycle of AAS would give the best results with the least amount of side effects. A dose of 250iu to 500iu everyday (ed) for 2 to 3 weeks is plenty and should very little from person to person (3). The Physicians Desk Reference recommends 500iu/day, as did the late, great, Dan Duchaine. The smaller doses are sufficient enough to begin reversal of testicular atrophy and used in conjunction with nolvade, will help the already present problem of recovery without raising the levels of estrogen to high and increasing the risk of gynecomastia in the user. Lower doses of 250iu to 500iu also avoid the further risk of down regulating LH receptors in the testes. The old saying more is better definitely does not apply to the use of HCG. You don´t want to finish PCT after using too much HCG only to find out your back at the beginning again. Your best bet is to start at 250iu or 500iu ed for 5 or 6 days, and if you don´t notice anything happening (nuts dropping and getting bigger) up the dose slightly. Small doses like 500iu two days a week isn´t going to cut it like some people think. The only thing small doses of HCG ay be useful (sublingually) for is reducing symptoms of benign prostatic hyperplasia (7). Yeah, that´s right, you can probably reduce some symptoms of an enlarged prostate with the use of small doses of HCG.
As stated above the cycles of HCG should be in the 2 to 3 week range with a least one month off in between, you could stretch your cycle out to four weeks without any major concern if you are using lower doses. One should however take care when using HCG as prolonged use could repress the body´s natural production of gonadotropins permanently, but this is mostly just pure speculation as it does not have yet to be reported nor has there been a case of an overdose. To be on the safe side shorter cycles of HCG seem to be that of the norm. Most users cycle HCG near the end of a steroid cycle, you should start your HCG therapy on the last week of your cycle. For best results you should also run nolva while you run HCG as taking HCG by itself will do little to nothing and gyno even though rare may also flair up. Once the HCG cycle is finished you continue with your usual clomid or nolvadex (preferably the latter) for pct as it is more effective when used in conjunction HCG for pct. With an AAS cycle of 6 to 10 weeks HCG may not be necessary unless extreme doses of AAS were used or there is an existing problem of testicular atrophy or you are running a heavy oral only cycle. AAS cycles of 12 or more weeks should have HCG as a part of post cycle plan.
HCG SIDE EFFECTS
Since HCG is used to stimulate testosterone production, side effects can be the same as those associated with AAS, although gyno may be more common. Possible side effects of HCG use are water and sodium retention after higher doses are used. This is usually a result of higher androgen production. It may cause gyno (again if doses are too high). Any athletes worried about failing urine test because of low levels of epitestosterone may find that using a dose of 500iu of HCG will increase epitestosterone levels. However the problem with HCG is that it is also banned by the IOC and can also be detected in a urine test, the half life of HCG is approximately 4 to 5 days. Another possible downside to HCG is that it to can be suppressive to natural testosterone because it takes the place of LH. Since LH is manufactured in the pituitary because of the response of GnRH (gonadotropin releasing hormone) which in turn is secreted by the hypothalamus. Because the HCG mimics LH and is being supplied exogenously the hypothalamus will be given a signal to still stop producing GnRH, so no natural LH will be produced (5). This is why it should always be used with a compound such as nolvadex. So although HCG is essential after long or heavy cycles, it should not be used without an ancillary such as (specifically) nolv. Also HCG therapy should be discontinued at least 2 weeks prior to stopping the use of nolva, or it may suppress natural testosterone itself (5). This should not be a problem if you are running it towards the end of your cycle of AAS and before pct.
The average price to buy HCG is between 10$ to 40$ per 5000iu with solvent, it comes in doses of 100, 125, 250, 500, 1000, 1500, 2000, 2500, 3000, 5000, 10000, 20000 all iu (international units).
HCG is readily available and can be found in almost all the places where you may find AAS. If you have a good source you should have no problems in obtaining this product. There are currently only a few fakes of HCG around, but most are few and far between. Since the powder of HCG is similar to the powder of somatropin often cheaper HCG is sold and marketed as the more expensive HGH (human growth hormone) on the black market.