hCG (human chorionic gonadotropin)
hCG is a hormone made by the placenta that is also produced as a prescription medicine. It is approved for some types of infertility in women, for certain men with low gonadotropin levels, and in the US for undescended testes in boys.
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What it is
Human chorionic gonadotropin (hCG) is a hormone made by the placenta during pregnancy. Medicinal hCG is either purified from urine, as in Pregnyl, or made by recombinant technology, as in choriogonadotropin alfa (Ovitrelle) [1, 2]. It is a prescription medicine given by injection under specialist supervision. In the UK it is also listed as a Class C controlled drug under the Misuse of Drugs Act 1971 [10].
How it works
hCG acts in almost the same way as luteinising hormone (LH), a hormone released by the pituitary gland [1]. It binds to the receptor that LH normally uses [2]. In men, this stimulates the Leydig cells of the testes to make testosterone. In women, it supports the corpus luteum, which makes progesterone, and can trigger the final release of an egg [1, 2]. After injection under the skin, recombinant hCG has a terminal half-life of about 30 hours [2].
Approved medical uses
- US: prepubertal cryptorchidism (undescended testes) without a physical blockage, selected cases of hypogonadotropic hypogonadism in males (low testosterone caused by low pituitary hormones), and induction of ovulation in some women with infertility [1].
- EU: recombinant hCG (Ovitrelle) is authorised to trigger final egg maturation in assisted reproduction such as IVF, and to trigger ovulation in women who do not ovulate regularly [2].
- The US label states that hCG has not been shown to be effective for treating obesity and that there is no substantial evidence it increases weight loss [1].
What the research shows
- Testosterone therapy and fertility. Testosterone treatment suppresses the pituitary signals the testes need to make sperm. The Endocrine Society recommends against testosterone therapy in men planning fertility in the near term [5], and the American Urological Association (AUA) says testosterone should not be prescribed to men currently trying to conceive [4].
- Hormone levels inside the testes. In a short study of 29 healthy men whose own LH had been suppressed by testosterone, adding hCG kept testosterone levels inside the testes within the normal range, with higher levels at the higher doses studied [3].
- Sperm production in men on testosterone. A retrospective review of 26 men with low testosterone treated with testosterone plus hCG found no man became azoospermic (no sperm in the semen) during follow-up, and semen measures did not change [6]. The study was small and had no comparison group [6].
- Recovery after testosterone use. A retrospective review from two infertility clinics looked at 49 men with absent or very low sperm counts linked to testosterone use. Sperm production returned in about 96% of them during hCG-based treatment by fertility specialists [7]. There was no control group, so the role of stopping testosterone versus the treatment itself is unclear.
- Guideline position. The AUA says clinicians may use hCG, aromatase inhibitors or selective oestrogen receptor modulators in men with testosterone deficiency who want to keep their fertility. This is a conditional recommendation based on lower-quality evidence, and these are off-label uses [4]. Reviewers describe these approaches as not well established and note that they carry side effects [8].
Known risks and side effects
- Ovarian hyperstimulation syndrome (OHSS) in women, which can be serious. It occurred in about 4% of women treated with Ovitrelle, and was severe in under 0.5% [2]. The US label also warns of ovarian cyst rupture [1].
- Multiple pregnancy, ectopic pregnancy and blood clots (thromboembolism) in women having fertility treatment [1, 2].
- Precocious puberty in boys treated for undescended testes [1].
- Not to be used in people with prostate cancer or other androgen-dependent tumours [1].
- Other reported effects include headache, irritability, restlessness, depression, tiredness, fluid retention (oedema), gynaecomastia (breast tissue growth in men), pain at the injection site and allergic reactions, including anaphylaxis [1].
- Pregnancy tests: hCG can cause false positive pregnancy test results for up to ten days after a dose [2].
- Sport: hCG is prohibited at all times in male athletes under the World Anti-Doping Agency (WADA) Prohibited List [9].
Blood tests commonly monitored
- Testosterone and pituitary hormones (LH, FSH): measured in clinical studies of men treated with hCG, because raising testosterone made by the testes is the intended effect [3, 6].
- Semen analysis: not a blood test, but used in studies to check sperm production [6, 7].
- Haemoglobin and haematocrit: the AUA recommends measuring these before starting testosterone therapy, which is relevant for men who are also prescribed testosterone [4].
- hCG level and pregnancy tests: results can be falsely positive for several days after treatment, so timing matters when interpreting them [2].
If you and your doctor are monitoring treatment, Enhanced Training Studio keeps a private log on your phone: what you take and when, your blood test results over time, and how you feel. How tracking works.
Sources
- US Food and Drug Administration. Pregnyl (chorionic gonadotropin for injection, USP) prescribing information. FDA, 2011. accessdata.fda.gov
- European Medicines Agency. Ovitrelle (choriogonadotropin alfa): EPAR product information. EMA. ema.europa.eu
- Coviello, et al. Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression. Journal of Clinical Endocrinology & Metabolism, 2005. academic.oup.com
- American Urological Association (Mulhall, et al.). Evaluation and Management of Testosterone Deficiency: AUA Guideline. Journal of Urology and auanet.org, 2018 (validity confirmed 2024). auanet.org
- Endocrine Society. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. Journal of Clinical Endocrinology & Metabolism, 2018. endocrine.org
- Hsieh TC, et al. Concomitant intramuscular human chorionic gonadotropin preserves spermatogenesis in men undergoing testosterone replacement therapy. Journal of Urology, 2013. PubMed
- Wenker, Dupree, Langille, Kovac, Ramasamy, Lamb, Mills, Lipshultz. The use of HCG-based combination therapy for recovery of spermatogenesis after testosterone use. Journal of Sexual Medicine, 2015. PubMed
- Herati AS, Kohn TP, Kassiri B. New frontiers in fertility preservation: a hypothesis on fertility optimization in men with hypergonadotrophic hypogonadism. Translational Andrology and Urology, 2020. PMC
- World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2026. WADA, 2025. Prohibited List 2026 (PDF copy hosted by CONMEBOL)
- UK Government. The Misuse of Drugs Act 1971 (Modification) Order 1996. legislation.gov.uk, 1996. legislation.gov.uk
Related
Last reviewed 7 October 2026. General information, not medical advice. Found a mistake? Email [email protected].