Definition
Human Chorionic Gonadotropin (HCG) is a hormone that is produced in the human placenta and plays an important role in maintaining pregnancy. The hormone consists of two subunits, alpha and beta. Only the beta subunit is characteristic, while the alpha subunit is also found in other hormones.
Function
The female cycle can be divided into two hormonal phases: This cycle must be interrupted when a fertilised egg (blastocyst) is implanted. For this purpose, some cells of the blastocyst, the syncytiotrophoblasts that develop into the fetal part of the placenta, produce human chorionic gonadotropin. Similar to the luteinizing hormone (LH) of the pituitary gland, HCG has a stimulating effect on the corpus luteum in the ovary and causes the ovarian body to maintain its production of estrogen and progesterone.
In the case of pregnancy, the corpus luteum does not regress until the 12th week – only at this point is the placenta capable of producing sufficient progesterone itself to maintain the pregnancy. In addition, the high levels of oestrogen and progesterone lead to the transformation of the uterine lining into the nutrient-rich decidua, which nourishes the embryo at the beginning. Negative feedback also prevents the release of stimulating hormones in the pituitary gland, so that no further ovulation occurs.
Value during pregnancy
In the first weeks of pregnancy, the HCG concentration in the blood rises sharply until it reaches its maximum around the eighth week of pregnancy. After that, the concentration drops again to just under 20% of the maximum value, which is reached around the 28th week of pregnancy. Before and after pregnancy the concentration is significantly lower.
Diet
In 1954, the British doctor Albert Simeons examined pregnant women who were on an ultra-low calorie diet. He found that when the diet was combined with hCG injections, the patients lost more fat than muscle tissue. Based on this observation, he recommended a restrictive diet with hCG injections.
Since then, this method has been in fashion again and again and is advertised, for example, as the method of choice by Hollywood actors. There has never been any evidence that the intake of pregnancy hormones supports weight loss and hCG is not approved for this purpose. With strict adherence to the recommended 500 kilocalorie diet (for comparison: the daily calorie requirement of an adult is about 2000kcal), any slimming effect can be attributed to the body’s negative energy balance through diet.
However, it has been proven that such diets do not lead to long-term success (yo-yo effect) and the risk of malnutrition is very high with such radical diets – with sometimes life-threatening consequences such as cardiac arrhythmia. Furthermore, the safety of hCG injections has not been sufficiently investigated. Procuring hCG on the Internet still carries the risk of purchasing preparations of poor pharmaceutical quality, which may contain other substances that are harmful to health. For this reason, from a medical point of view, hCG-based diets are strongly discouraged.
