Chemical Characteristics of HCG
Human Chorionic Gonadotropin (HCG) is a protein (or peptide) hormone, but it is more specifically referred to as an oligosaccharide glycoprotein (a protein molecule that contains one or more carbohydrates/sugar molecules affixed to it as well). Its protein structure consists of an amino acid chain of 244 amino acids, with a sub-unit of 92 amino acids on it that is 100% identical to LH and FSH. It is this subsection of the HCG molecule that enables it to mimic the action of LH and FSH 100% identically on the same receptors in the cells that LH and FSH activate.
Properties of HCG
HCG’s primary purpose is that of either the treatment of female infertility, or for the use of stimulating and/or increasing endogenous Testosterone production in men.
HCG is generally very well tolerated by the majority of men who utilize it for hormonal recovery following the cessation of an anabolic steroid cycle. There are only but two HCG side effects worth noting that every individual must be aware of prior to engaging in use, especially since there have existed a plethora of misconceptions in regards to HCG ever since its introduction into the world of anabolic steroid use.
It has been previously covered in this profile that HCG will increase testicular aromatase activity, which can result in the manifestation of Estrogenic side effects as a result of increased Estrogen generated by aromatization (conversion) of androgens into Estrogen. It has therefore been recommended that individuals utilize an aromatase inhibitor (AI) during HCG use, and as previously outlined, the most suitable AI for this purpose is Aromasin (Exemestane). Other AIs can be utilized as well, but the common PCT protocol of HCG, Nolvadex, and an aromatase inhibitor will present problems if the other two commonly known AIs are used (Letrozole and Arimidex). This has been covered extensively in the HCG doses portion of this profile. If an AI is not utilized to lower circulating levels of aromatase, and subsequently Estrogen, then not only will Estrogenic side effects result, but an impairment of endogenous HPTA function will result. This will be counterproductive to the original goal of restoration of hormonal function. Estrogenic side effects include the following: water retention and bloating, blood pressure elevations (as a result of the water retention), increased possible fat retention/gain, and gynecomastia.
Androgenic Side Effects
Androgenic side effects are indeed a part of HCG side effects due to the fact that HCG will increase circulating blood plasma levels of androgens, notably Testosterone, and subsequently Dihydrotestosterone. This is a naturally expected and desired effect of HCG use. Androgenic side effects include: increased sebum secretion (oily skin), increased bouts of acne (linked to increased sebum secretion), bodily and facial hair growth, benign prostatic hypertrophy (BPH), and the increased risk of triggering Male Pattern Baldness (MPB) in individuals that possess the genetic trait required for the condition to manifest itself.
 Exogenous stimulation of corpus luteum formation in the rabbit; influence of extracts of human placenta, decidua, fetus, hydatid mole and corpus luteum on the rabbit gonad. Hirose T 1920 J Jpn Gynecol Sot 16:1055.
 Die Schwangerschaftsdiagnose ausdem Ham durch Nachweis des Hypophysenvorderlappen-hormone.11. Pracktishe und theoretische Ergebnisse aus den hamuntersuchungen. Ascheim S/ Zondek B 1928 Klin Wochenschr 7:1453-1457.
 The effect of human chorionic gonadotropin (HCG) in the treatment of obesity by means of the Simeons therapy: a criteria-based meta-analysis. Lijesen GKS, et al. Br J Clin Pharmacol1995; 40: 237-43.