Human Chorionic Gonadotropin (hCG)
FDA ApprovedAlso known as: hCG, Choriogonadotropin, Pregnyl, Novarel, Ovidrel, Choragon, Profasi, Choriomon
A glycoprotein hormone FDA-approved for ovulation induction, cryptorchidism, and hypogonadotropic hypogonadism. Functions as an LH receptor agonist with over 50 years of clinical use in reproductive medicine. Gold standard trigger for assisted reproductive technology.
Research Statistics
FDA-approved glycoprotein hormone with decades of global trials and fully established mechanism.
Research Dossier
Overview
What is Human Chorionic Gonadotropin (hCG) and what does the research say?
Mechanism of Action
hCG is a well-characterized hormone with extensive human clinical evidence spanning over 50 years. Its mechanisms are firmly established through receptor studies, clinical trials, and decades of therapeutic use.
How It Works (Simplified)
hCG mimics luteinizing hormone (LH) but lasts much longer in the body, providing sustained receptor stimulation:
Binds LHCGR on ovarian follicles, triggering final oocyte maturation and predictable ovulation 36-40 hours post-injection.
Stimulates Leydig cells in testes to produce testosterone, maintaining intratesticular levels critical for spermatogenesis.
Maintains corpus luteum function, ensuring progesterone production needed to support early pregnancy until placental takeover.
Half-life of 24-36 hours (vs LH’s 20 minutes) due to extensive glycosylation and C-terminal extension, enabling single-dose efficacy.
Scientific Pathways
LHCGR/cAMP Pathway (Primary Signaling)
hCG binds LHCGR extracellular domain
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Receptor activation (conformational change)
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Galphas protein --> adenylyl cyclase --> cAMP increase
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Protein kinase A (PKA) activation
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+-- Ovary: Meiosis resumption, cumulus expansion, ovulation
+-- Testis: StAR/P450c17 activation, testosterone synthesis
+-- Corpus luteum: Progesterone biosynthesisKey Research: Youssef MA et al. Cochrane systematic review (2014) established hCG as gold standard ovulation trigger with higher live birth rates than GnRH agonist in fresh IVF cycles. PMID:25358904
Important Limitations
- OHSS Risk: Primary safety concern; hCG’s sustained LHCGR stimulation can cause ovarian hyperstimulation syndrome in susceptible patients
- Not for weight loss: FDA has warned against hCG use for weight loss (ineffective and potentially harmful)
- Requires monitoring: Fertility applications require physician oversight and ultrasound monitoring
- WADA prohibited: Banned in male athletes due to testosterone-stimulating effects
Evidence-Chained Benefits
Evidence-Chained Benefits
Research findings linked to mechanisms and clinical outcomes
What to Expect
Timeline based on observations from published studies. Individual responses may vary.
Rapid absorption following subcutaneous or intramuscular injection. Peak serum levels reached within 4-12 hours depending on formulation (recombinant vs urinary-derived).
Ovulation occurs approximately 36-40 hours post-trigger injection in fertility protocols. This predictable timing enables precise scheduling of egg retrieval or timed intercourse.
Sustained LHCGR stimulation due to 24-36 hour half-life. In males, testosterone elevation persists for several days. Corpus luteum support maintained through this period.
With continued administration in TRT protocols, intratesticular testosterone maintained at near-baseline levels. Spermatogenesis preserved with ongoing treatment.
Research-Based Observations
This timeline reflects observations from published clinical and preclinical studies. Individual responses may vary significantly. This is not a guarantee of effects or a dosing schedule. Consult qualified healthcare providers for personalized guidance.
Quality Checklist
Visual indicators to help evaluate Human Chorionic Gonadotropin (hCG) product quality
Good Signs (6 indicators)
Warning Signs (5 indicators)
Bad Signs (6 indicators)
For Research Evaluation Only
These quality indicators are general guidelines based on typical peptide characteristics. Professional laboratory testing (HPLC, mass spectrometry) provides definitive quality verification. This checklist is for initial visual evaluation only.
Peptide Interactions
Known and theoretical interactions when combining Human Chorionic Gonadotropin (hCG) with other peptides. Based on published research and mechanistic considerations.
Kisspeptin
SynergisticKisspeptin stimulates endogenous GnRH/LH release while hCG provides direct LHCGR agonism. Combined use studied for ovulation induction with potentially reduced OHSS risk. Clinical trials support sequential administration.
Gonadorelin
SynergisticGnRH pulses restore HPG axis function while hCG provides direct gonadal stimulation. Used sequentially in hypogonadotropic hypogonadism treatment protocols.
Sermorelin
CompatibleDifferent axes of action (GH vs gonadal). No known interactions; commonly used together in hormone optimization protocols.
BPC-157
CompatibleNon-overlapping mechanisms. BPC-157 focuses on tissue repair while hCG acts on gonadal function. No interaction data available.
PT-141
CautionBoth affect reproductive/sexual function through different mechanisms. PT-141 acts on melanocortin receptors while hCG stimulates gonadal hormone production. Monitor for additive effects.
Clomiphene
CautionBoth stimulate gonadal function. Clomiphene via SERM action increasing LH, hCG via direct LHCGR agonism. Combined use requires careful monitoring for overstimulation.
Research Note: Interaction data is based on published literature, mechanistic understanding, and theoretical considerations. Most peptide combinations lack direct clinical study. This information is for educational purposes only and does not constitute medical advice. Always consult qualified healthcare providers.
References
Key Studies Cited
Full reference list available on request. All citations link to PubMed for verification.
Methodology Note
This dossier synthesizes available evidence from peer-reviewed literature, regulatory documents, and clinical trial registries. Evidence strength ratings follow a modified GRADE approach.
For complete methodology details, see our Methodology page.
Important Disclaimer
This dossier is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before making health decisions.
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