What Does HCG Do to a Woman's Body?
In pregnant women, the primary role of the hCG hormone is to promote the production of progesterone by the ovaries until the placenta is well developed.

The human chorionic gonadotropin (hCG) hormone is naturally produced in pregnant women and is referred to as the pregnancy hormone. A very small amount is produced in nonpregnant women, but it has no significant function.

Effects of the hCG hormone on women are described below.


The hCG hormone is given along with other drugs to treat infertility.

  • It supports normal egg development in the ovaries and stimulates the ovary to release eggs during ovulation, increasing the probability of becoming pregnant.
  • The U.S. Food and Drug Administration (FDA) approved the use of hCG injections for infertility.
  • A shot of hCG is referred to as a trigger shot, and once given, it triggers ovulation in about 36 hours.


Immediately after implantation of the fertilized egg into the uterine wall, hCG hormone production begins in women.

  • It usually takes 8 to 14 days for hCG levels to increase sufficiently in the blood and urine, and it is detected using an at-home pregnancy test.
  • The hCG hormone is produced by the placenta during pregnancy, and it is seen in the blood and urine throughout the entire pregnancy.

The primary role of the hCG hormone is to promote the production of the hormone progesterone by the ovaries until the placenta is well developed. A developed placenta can produce significant levels of progesterone, which occurs about 10 weeks of gestation.

  • Progesterone is essential to maintain a healthy pregnancy and prevent miscarriages. 
  • The hCG hormone helps prolong the pregnancy in the initial stages.
  • It affects the development of the fetus and the uterus before the production of the hormone progesterone begins.

Levels of the hCG hormone are high during the first three months of pregnancy and reduce gradually.

Weight loss

The hCG diet was a popular alternative among people who attempt to reduce weight. It is a very controversial diet, not only because of its effect but also because of its safety.

The hCG diet consists of consuming just 500 calories per day for several weeks, along with daily injections or administration of the hCG hormone.

  • There is no evidence of the role of the hCG hormone in increasing metabolism and treating obesity.
  • It was made popular by health enthusiasts and commercial supplement sellers, claiming that it works wonders for weight loss.

The research concluded that weight loss is probably achieved by the ultra-low-calorie diet but not the hCG hormone.

The FDA does not regulate food supplements but declared it is harmful and illegal to consume any food supplements with hCG. Furthermore, it banned taking hCG injections for weight loss.

What do abnormal levels of hCG indicate?

Abnormal levels of human chorionic gonadotropin (hCG) may indicate the following:

  • During pregnancy:
    • Levels of the human chorionic gonadotropin (hCG) hormone in the blood determines the situation of pregnancy, and abnormally high or low levels of the hCG hormone may indicate any abnormalities.
  • High levels of the hCG hormone are seen in:
    • Multiple pregnancies such as twins or triplets.
  • Low levels of the hCG hormone are seen in:
    • Ectopic pregnancy (implantation of the embryo occurs somewhere other than the uterus, such as the fallopian tube).
    • Miscarriages.
  • In nonpregnant women:
    • Nonpregnant women may generate a moderate to the high amount of the hCG hormone due to the following:
    • Malignancies:
      • Breast
      • Ovary
      • Kidney
      • Lungs
      • Gastrointestinal tract
      • Trophoblastic disease (a tumor developed from the placental cells; it is a noncancerous condition but may become cancerous)
    • The hCG hormone in the blood and urine serves as tumor markers.
  • Medical conditions:
    • Excessive production of the hCG hormone by the pituitary gland in perimenopausal or postmenopausal women
    • Phantom hCG (high levels of the hCG hormone in the body without any underlying cause)


The first sign of pregnancy is most often: See Answer

What are the side effects of injectable hCG?

A human chorionic gonadotropin (hCG) injection is given under the skin or to the muscle. 

Side effects associated with injectable hCG include:

  • Blood clots formation:
  • Ovarian hyperstimulation syndrome (OHSS):
  • Multiple pregnancies:
    • The hCG hormone may increase the chances of multiple pregnancies, which is a high risk for both mother and babies. It helps with infertility and results in pregnancy, but it is recommended to discontinue hCG immediately after conceiving.

Less serious side effects

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Medically Reviewed on 1/6/2022
Image Source: iStock Images

Human Chorionic Gonadotropin Hormone (HCG): https://www.hormone.org/your-health-and-hormones/glands-and-hormones-a-to-z/hormones/human-chorionic-gonadotropin-hormone-hcg

Human Chorionic Gonadotropin Hormone (HCG): https://www.uofmhealth.org/health-library/hw42062

Human chorionic gonadotropin: https://www.yourhormones.info/hormones/human-chorionic-gonadotrophin/