Human chorionic gonadotropin (HCG) is a hormone best known for its role in pregnancy. It is produced primarily by the placenta, and sends essential signals that support implantation, sustain pregnancy, and promote healthy foetal development.

While this highlights how it could be important for women struggling to conceive or carry a pregnancy to term, HCG’s therapeutic potential extends beyond pregnancy. In fact, this hormone has a range of clinical applications for both women and men, which we will cover in this article.

Mechanism of Action

HCG is closely related to other hormones such as luteinising hormone (LH) and follicle-stimulating hormone (FSH). Both HCG and LH bind to the same receptor, stimulating testosterone production and triggering pathways important in reproductive processes¹. HCG secretion from the placenta can increase in response to gonadotropin-releasing hormone (GnRH).

This hormone works by:

Binding to the luteinizing hormone/choriogonadotropin receptor (LHCGR), triggering signalling that activates pathways responsible for steroidogenesis, cell proliferation and other reproductive functions.
Recruiting β-arrestins, which may help to balance the production of progesterone and testosterone and enhance steroidogenesis².
Influencing endometrial receptivity, angiogenesis, and immune modulation during pregnancy through the activation of multiple pathways³.

HCG’s Role in Women’s Health

Since HCG is naturally produced by the placenta, it would normally only be able to exert its benefits once a woman becomes pregnant, and its signalling focuses on promoting activities that support pregnancy, including:

Stimulating leukaemia inhibitory factor (LIF): LIF is involved in development, immunomodulation, promotion of cell survival and stem cell maintenance.
Regulates interleukin-6: IL-6 is involved in both immunity and inflammation. If levels are elevated or insufficient, this can lead to complications in pregnancy⁴.
Promoting angiogenesis and vasculogenesis in the uterine lining: This helps to ensure that there is an adequate blood supply to the embryo as it develops⁵.

Clinical and Investigational Applications of HCG in Women

HCG has several therapeutic applications, including:

Assisted reproductive technologies (ART): It can be used to induce ovulation and support the luteal phase by mimicking the effect of LH-induced oocyte maturation⁶. It can make the endometrial lining more receptive to implantation by promoting angiogenesis and preventing the immune system from attacking the embryo. A meta-analysis reported that it can significantly increase the chances of pregnancy and implantation when given as an intrauterine injection⁷.
Pregnancy testing: Since this hormone is typically only present after implantation of an embryo, its detection is used to confirm a pregnancy⁸.
Detecting disorders in pregnancy: Unusual HCG levels can indicate an ectopic pregnancy, miscarriage or gestational trophoblastic disease⁹. It may also indicate chromosomal abnormalities of the foetus¹⁰.

It is being investigated for its potential use in:

Recurrent pregnancy loss: Since it can promote blood flow to the embryo and prevent rejection by the immune system, it is hoped that HCG may help reduce the chance of miscarriage in women who have experienced multiple losses, however, studies have yielded mixed results as to its efficacy¹¹.

HCG’s Role in Men’s Health

Since it is synthesised and released by placental cells in response to GnRH, and men do not carry placental tissue, GnRH is not known to increase HCG levels. Instead, HCG is produced by the pituitary gland in men. Under certain circumstances, such as during androgen deprivation therapy, HCG levels can become elevated. HCG and LH are both regulated by the same feedback mechanism, so levels of each of these hormones tend to mirror each other. Both also bind to the same receptors in the testes to stimulate testosterone production.

Clinical and Investigational Applications of HCG in Men

The ability of HCG to promote testosterone production in men means that it can be used therapeutically to:

Treat hypergonadotropic hypogonadism (HH) and infertility: It improves sperm recovery rate and is usually combined with FSH or human menopausal gonadotropin (HMG) to achieve even more pronounced results. A meta-analysis reported a 40% spermatogenesis rate with HCG treatment, but this increased to 86% when combined with FSH^13,14. In patients with HH and micropenis, HCG has been shown to increase penile length, with one study reporting almost a 2cm increase in flaccid length after 24 weeks of treatment¹⁵.
Induce puberty: In adolescents with HH, it can be used either alone or with FSH to induce puberty, testicular growth and promote virilisation¹³.
Restore fertility after testosterone therapy: HCG can be used alone or with FSH to help restore spermatogenesis in men who have become infertile due to exogenous testosterone or anabolic steroid use, even if testosterone is continued^16,17.
Increase testosterone: HCG can be used instead of testosterone therapy to maintain endogenous testosterone and fertility in men with secondary hypogonadism¹⁸.
Reduce the harm to androgen users: In those unwilling to stop androgen use, it helps to reduce the impact of these drugs on male fertility¹⁹.

HCG can improve body composition and metabolic health by stimulating endogenous testosterone production while avoiding the negative effects associated with exogenous testosterone use, such as reduced fertility. This makes it ideal for therapies aimed at improving male fertility and mitigating exogenous androgen-induced harm.

Other Effects of HCG Treatment

HCG can affect other aspects of health for which it is not prescribed:

Increase in libido: Men who have taken HCG for low testosterone symptoms tend to experience an increase in libido and improvements in erectile function^20,21. In women, it does not appear to elicit any significant change in libido.
Anti-inflammatory activity: HCG increases regulatory T-cells and reduces pro-inflammatory immune cells. As mentioned earlier, this helps to increase the chances of a successful pregnancy²², but this activity is also exerted when it is given outside of pregnancy²³. As such, it is being investigated for its potential use in autoimmune diseases such as multiple sclerosis²⁴ and autoimmune hepatitis²⁵.

Factors That Affect the Efficacy and Behaviour of HCG in Humans

There is evidence that HCG can influence the distribution of fat in the body, which, given that HCG/LH receptors are present in adipose tissue, should not come as a surprise. One study demonstrated its ability to increase fat accumulation²⁶, a function that may be responsible for the weight gain experienced by women in early pregnancy. Interestingly, animal studies have found that HCG may reduce weight in obese rats when they are fed a calorie-restricted diet^27,28 HCG may therefore have different effects on metabolism depending on the physiological context.

Side Effects and Safety

When used in controlled, therapeutic settings, HCG is generally considered safe, with few adverse events. Side effects can include:

Gynecomastia
Fluid retention
Ovarian hyperstimulation syndrome (OHSS)
Thromboembolism^29–33

Conclusion

HCG is a hormone essential for supporting the growth and development of an embryo. It can improve both female and male fertility, so it is used in fertility treatments for women and to treat hypogonadism in men. There have been conflicting results from studies that have investigated its use as a weight loss drug, indicating that the situational use has a significant effect on how it signals in the body. It is considered generally safe, with few serious adverse events having been reported.

Buy HCG here.

References

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Riccetti L, Yvinec R, Klett D, et al. Human Luteinizing Hormone and Chorionic Gonadotropin Display Biased Agonism at the LH and LH/CG Receptors. Sci Rep. 2017;7(1):940. doi:10.1038/s41598-017-01078-8
Wang W, Ge L, Zhang L, et al. Mechanism of human chorionic gonadotropin in endometrial receptivity via the miR ‐126‐3p/ PI3K /Akt/ eNOS axis. Kaohsiung J Med Sci. 2023;39(5):468-477. doi:10.1002/kjm2.12672
Prins JR, Gomez-Lopez N, Robertson SA. Interleukin-6 in pregnancy and gestational disorders. J Reprod Immunol. 2012;95(1):1-14. doi:10.1016/j.jri.2012.05.004
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Conforti A, Longobardi S, Carbone L, et al. Does Intrauterine Injection of hCG Improve IVF Outcome? A Systematic Review and a Meta-Analysis. Int J Mol Sci. 2022;23(20):12193. doi:10.3390/ijms232012193
Wilcox AJ, Weinberg CR, O’connor JF, et al. Incidence of Early Loss of Pregnancy. Obstet Gynecol Surv. 1989;44(2):147.
Braunstein GD, Karow WG, Gentry WC, Rasor J, Wade ME. First-trimester chorionic gonadotropin measurements as an aid in the diagnosis of early pregnancy disorders. Am J Obstet Gynecol. 1978;131(1):25-32. doi:10.1016/0002-9378(78)90469-6
Bogart MH, Pandian MR, Jones OW. Abnormal maternal serum chorionic gonadotropin levels in pregnancies with fetal chromosome abnormalities. Prenat Diagn. 1987;7(9):623-630. doi:10.1002/pd.1970070904
Morley LC, Simpson N, Tang T. Human chorionic gonadotrophin (hCG) for preventing miscarriage. Cochrane Database Syst Rev. 2013;(1). doi:10.1002/14651858.CD008611.pub2
Yoshimura K, Nakashima Y, Sugiyama K, Kohei N, Takizawa A. Supposed pituitary-production of human chorionic Gonadotropin induced by androgen deprivation therapy. Int Braz J Urol. 2019;45(1):38-44. doi:10.1590/s1677-5538.ibju.2017.0654
Alexander EC, Faruqi D, Farquhar R, et al. Gonadotropins for pubertal induction in males with hypogonadotropic hypogonadism: systematic review and meta-analysis. Eur J Endocrinol. 2024;190(1):S1-S11. doi:10.1093/ejendo/lvad166
Liu Y, Ren XY, Peng YG, et al. Efficacy and safety of human chorionic gonadotropin combined with human menopausal gonadotropin and a gonadotropin-releasing hormone pump for male adolescents with congenital hypogonadotropic hypogonadism. Chin Med J (Engl). 2021;134(10):1152. doi:10.1097/CM9.0000000000001419
Kim SO, Ryu KH, Hwang IS, Jung SI, Oh KJ, Park K. Penile Growth in Response to Human Chorionic Gonadotropin (hCG) Treatment in Patients with Idiopathic Hypogonadotrophic Hypogonadism. Chonnam Med J. 2011;47(1):39-42. doi:10.4068/cmj.2011.47.1.39
Wenker EP, Dupree JM, Langille GM, et al. The Use of HCG‐Based Combination Therapy for Recovery of Spermatogenesis after Testosterone Use. Published online June 2015. Accessed December 18, 2025. https://hdl.handle.net/2027.42/111925
Stocks BT, Oppenheimer AG, Campbell KJ, et al. Optimal restoration of spermatogenesis after testosterone therapy using human chorionic gonadotropin and follicle-stimulating hormone. Fertil Steril. 2025;123(4):607-615. doi:10.1016/j.fertnstert.2024.10.019
Fink J, Schoenfeld BJ, Hackney AC, Maekawa T, Horie S. Human chorionic gonadotropin treatment: a viable option for management of secondary hypogonadism and male infertility. Expert Rev Endocrinol Metab. 2021;16(1):1-8. doi:10.1080/17446651.2021.1863783
Rizzuti A, Alvarenga C, Stocker G, Fraga L, Santos HO. Early Pharmacologic Approaches to Avert Anabolic Steroid-induced Male Infertility: A Narrative Review. Clin Ther. 2023;45(11):e234-e241. doi:10.1016/j.clinthera.2023.09.003
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Madhusoodanan V, Patel P, Lima TFN, et al. Human Chorionic Gonadotropin monotherapy for the treatment of hypogonadal symptoms in men with total testosterone > 300 ng/dL. Int Braz J Urol. 2019;45(5):1008-1012. doi:10.1590/s1677-5538.ibju.2019.0132
Furcron AE, Romero R, Mial TN, et al. Human Chorionic Gonadotropin Has Anti-Inflammatory Effects at the Maternal-Fetal Interface and Prevents Endotoxin-Induced Preterm Birth, but Causes Dystocia and Fetal Compromise in Mice1. Biol Reprod. 2016;94(6). doi:10.1095/biolreprod.116.139345
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Juriol L, Valeff N, Dibo M, Ventimiglia MS, Correale J, Jensen F. Human chorionic gonadotropin regulates cytokine production by lymphocytes from patients with multiple sclerosis. J Reprod Immunol. 2024;164:104280. doi:10.1016/j.jri.2024.104280
Steinmetz C, Kashyap A, Zhivkova N, et al. Activation of silent mating type information regulation 2 homolog 1 by human chorionic gonadotropin exerts a therapeutic effect on hepatic injury and inflammation. Hepatology. 2017;65(6):2074-2089. doi:10.1002/hep.29072
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Chang P, Kenley S, Burns T, et al. Recombinant human chorionic gonadotropin (rhCG) in assisted reproductive technology: results of a clinical trial comparing two doses of rhCG (OvidrelR) to urinary hCG (ProfasiR) for induction of final follicular maturation in in vitro fertilization–embryo transfer. Fertil Steril. 2001;76(1):67-74. doi:10.1016/S0015-0282(01)01851-9
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Why should I use SARMs?

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What are SARMs?

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