HCG

HCG Peptide

Human chorionic gonadotropin (HCG) is a heterodimeric glycoprotein hormone composed of an alpha and a beta subunit. The alpha subunit is structurally related to luteinizing hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH), while the beta subunit is unique to HCG and confers receptor specificity. In research settings, HCG binds the LH/chorionic gonadotropin receptor (LHCGR) and may initiate cAMP-dependent signaling linked with gonadal steroidogenesis.

HCG has been examined for its potential to trigger final follicular maturation and ovulation, to support corpus luteum progesterone output in early pregnancy models, and to stimulate Leydig-cell testosterone synthesis. Owing to its longer biological half-life compared with LH, HCG is frequently used as a sustained LH analog in experimental systems to probe reproductive endocrine function and downstream tissue responses.

Overview

HCG is produced by trophoblast cells and is central to early pregnancy physiology, where it helps maintain the corpus luteum and progesterone production. Through LHCGR activation, HCG may drive intracellular cAMP signaling and downstream protein kinase pathways in gonadal cells. In female models, HCG is used to induce ovulation and luteinization; in male models, HCG can stimulate testosterone synthesis and support spermatogenesis when endogenous LH is deficient or suppressed. Very high HCG levels can also interact weakly with thyroid receptors, which is relevant to certain gestational and trophoblastic conditions. Because it is secreted in large quantities during pregnancy and by some tumors, HCG additionally serves as a well-established biochemical marker in research and diagnostic workflows.

Chemical Makeup

Molecular Weight: ~36.7 kDa (heterodimer)

Subunit Masses (COA): α-subunit 10,205 Da; β-subunit 15,547 Da

Other Known Titles: Human chorionic gonadotropin; Choriogonadotropin; hCG

CAS: 9002-61-3

Research and Clinical Studies

HCG Peptide and Fertility Support

In female reproductive models and assisted-reproduction protocols, HCG is presented as an LH surrogate to trigger final follicular maturation and ovulation. A single timed HCG exposure can prompt oocyte release and luteinization, supporting corpus luteum function and progesterone output. These applications mirror the physiologic LH surge and are widely used to coordinate ovulation and early luteal support in controlled settings.

HCG Peptide and Testosterone Stimulation

In male models, HCG engages LHCGR on Leydig cells to stimulate testosterone production. Research indicates that exogenous HCG can restore or maintain intratesticular testosterone and support spermatogenesis when pituitary gonadotropins are low or pharmacologically suppressed. HCG is therefore used to model LH activity in studies of hypogonadism, fertility preservation, and recovery from gonadotropin suppression.

HCG Peptide and Weight Management

Historical regimens combining HCG with severe caloric restriction have been investigated for weight loss; controlled studies and reviews have reported that HCG does not increase weight reduction or alter fat distribution beyond the effects of diet alone. In research summaries, any observed weight changes are attributed to energy restriction rather than a direct effect of HCG.

HCG Peptide and Endocrine Function

At very high concentrations, HCG can exert weak thyroid-stimulating activity due to structural similarity among glycoprotein hormones, and markedly elevated HCG has been associated with gestational hyperthyroid states in specific contexts. HCG is also produced ectopically by certain neoplasms, where it functions as a tumor marker and can contribute to endocrine findings in research and diagnostic settings. Its extended biological half-life relative to LH provides prolonged receptor stimulation, which is frequently leveraged in experimental designs.

HCG Peptide is available for research and laboratory purposes only. Please review and adhere to our Terms and Conditions before ordering.

References

1. Humaidan P, Alsbjerg B. GnRHa trigger for final oocyte maturation: is HCG trigger history? Reprod Biomed Online. 2014;29(3):274–280 rbmojournal.com.
2. Coviello AD, Matsumoto AM, Bremner WJ, et al. Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression. J Clin Endocrinol Metab. 2005;90(5):2595–2602 pubmed.ncbi.nlm.nih.gov.
3. Fink J, Schoenfeld BJ, Hackney AC, et al. Human chorionic gonadotropin treatment: a viable option for management of secondary hypogonadism and male infertility. Expert Rev Endocrinol Metab. 2021;16(1):1–8 pubmed.ncbi.nlm.nih.gov.
4. Lee JA, Ramasamy R. Indications for the use of human chorionic gonadotropic hormone for the management of infertility in hypogonadal men. Transl Androl Urol. 2018;7(Suppl 3):S348–S352 imcwc.com.
5. Habous M, Giona S, Tealab A, et al. Clomiphene citrate and human chorionic gonadotropin are both effective in restoring testosterone in hypogonadism: a short-course randomized study. BJU Int. 2018;122(5):889–897 tau.amegroups.org.
6. Liu PY, Wishart SM, Handelsman DJ. A double-blind, placebo-controlled trial of recombinant human chorionic gonadotropin in older men with partial age-related androgen deficiency. J Clin Endocrinol Metab. 2002;87(7):3125–3135 tau.amegroups.org.
7. ClinicalTrials.gov. Efficacy and Safety of Long Term Use of hCG or hCG Plus hMG in Males With Isolated Hypogonadotropic Hypogonadism (IHH). (Tongji Hospital study NCT03687606) centerwatch.com.

Dr. Marinov

Dr. Marinov (MD, Ph.D.) is a researcher and chief assistant professor in Preventative Medicine & Public Health. Prior to his professorship, Dr. Marinov practiced preventative, evidence-based medicine with an emphasis on Nutrition and Dietetics. He is widely published in international peer-reviewed scientific journals and specializes in peptide therapy research.