hCG (human chorionic gonadotropin): effects, uses and side effects
Clinical review pending
How hCG is used for certain fertility problems and hormone deficiencies, what studies have found, and which side effects can occur.
The hormone hCG is used to trigger ovulation in certain fertility problems. Other uses include hormonally caused underactivity of the testes in men and certain forms of undescended testes in boys. hCG has no demonstrated effect as a weight-loss treatment and is not approved for that purpose in the United States. 2
What is human chorionic gonadotropin?
Human chorionic gonadotropin, or hCG, is a glycoprotein hormone: a protein with sugar components attached. The placenta normally produces it during pregnancy. FDA-approved injectable preparations such as Pregnyl and Novarel contain purified hCG from the urine of pregnant women. Choriogonadotropin alfa (Ovidrel), a laboratory-made recombinant version, is also available.
hCG resembles luteinizing hormone (LH) in structure and action. The pituitary gland produces LH, which helps regulate ovarian and testicular function.
How does human chorionic gonadotropin work?
hCG binds to the same receptor as luteinizing hormone, the LH/CG receptor. It mimics the natural midcycle LH surge. During fertility treatment, other hormones first stimulate the growth of follicles in which eggs mature. A subsequent hCG dose triggers the final maturation and release of the egg.
In men, hCG stimulates the Leydig cells in the testes to produce testosterone and supports sperm production. It is therefore used in hypogonadotropic hypogonadism. In this form of testicular underactivity, there are insufficient hormonal signals stimulating the testes to function. In boys with undescended testes, the testosterone produced in response to hCG can promote testicular descent, provided there is no anatomical cause.
A Cochrane review compared urinary hCG with recombinant hCG for final egg maturation. Across seven studies involving 1,136 women, ongoing pregnancy or live birth rates were similar. The odds ratio, a statistical measure of comparison, was 1.15; its 95% confidence interval ranged from 0.89 to 1.49, describing the uncertainty of that estimate. The result does not establish a clear advantage for either form. 1
Some commercial diet programs promote hCG for weight loss. The FDA explicitly states that such an effect has not been demonstrated and that hCG is not approved for this purpose. 2
Is hCG FDA-approved?
Yes. Injectable hCG preparations have been approved in the United States for decades for certain hormonal indications: triggering ovulation, treating certain forms of male hypogonadism, and treating cryptorchidism, the medical term for undescended testes. 3
This approval does not extend to weight loss. The FDA has specifically warned about unapproved, over-the-counter “homeopathic” hCG products marketed for that purpose. Prescription hCG is not approved for weight loss either. 2
What is human chorionic gonadotropin prescribed for?
In carefully selected cases of female infertility, hCG may be used to trigger ovulation and enable pregnancy. Beforehand, follicle-stimulating hormone (FSH) or menotropins stimulate follicular development.
Men receive hCG to treat hypogonadotropic hypogonadism. In prepubertal boys, it may be used for undescended testes when no anatomical obstruction prevents testicular descent.
The studies in men listed here show how testosterone levels changed during treatment. They were small or lasted only a short time:
| Study | Participants | Result |
|---|---|---|
| A 2021 systematic review including 5 hCG studies 4 | 196 men | Mean total testosterone rose from 284.5 to 565.6 ng/dL. 4 |
| A 2018 randomized trial of clomiphene, hCG or a combination of both 5 | 282 men with hypogonadism who wanted to preserve fertility | Testosterone increased in all 3 treatment arms. 5 |
What side effects can occur?
The prescribing information lists side effects including: 3
- Injection-site pain
- Headaches
- Fluid retention, also called edema
- Breast tenderness or gynecomastia, an enlargement of breast gland tissue in male patients
- Irritability, restlessness and depression
More serious risks include:
- Ovarian hyperstimulation syndrome, in which the ovaries respond excessively to hormonal stimulation, and multiple pregnancies during fertility treatment
- Signs of early puberty in boys treated for undescended testes
- Rare arterial thromboembolic events, in which blood clots block arteries