HCG is a hormonal regulation research compound currently in stock directly from a verified Chinese manufacturer. Every batch is HPLC-verified and shipped with a Certificate of Analysis (COA). Sourcing is direct — no intermediaries. Minimum order value is $600 USD. International shipping available.
Human chorionic gonadotropin (HCG) is a glycoprotein hormone structurally homologous to luteinising hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH). It is a heterodimer consisting of a non-covalently associated alpha subunit (92 amino acids, common to all four glycoprotein hormones) and a beta subunit (145 amino acids, unique to HCG and responsible for receptor specificity) — linked by two N-linked and four O-linked oligosaccharide chains that account for approximately 30% of the total molecular weight and are essential for biological activity and plasma half-life. The high-affinity binding of the HCG beta subunit to the LH receptor (LHCGR) enables it to mimic and sustain LH signalling, most critically the sustained Leydig cell testosterone stimulation that maintains corpus luteum function in early pregnancy. For research applications, recombinant or urinary-derived HCG is used as an LH receptor agonist in reproductive biology, HPG axis pharmacology, and steroidogenesis studies.
The research utility of HCG spans endocrine and reproductive biology: it is the standard positive control for LH receptor activation assays, the reference agonist for Leydig cell testosterone production studies, and a tool compound for HPG axis suppression-recovery protocols in male reproductive research models. HCG's longer half-life than native LH (t½ ~24–36 h vs. ~1 h for LH) makes it the preferred ligand for sustained receptor stimulation in prolonged in vitro or in vivo assays. In hypothalamo-pituitary-gonadal (HPG) axis research, the HCG stimulation test — measuring testosterone response to a defined HCG dose — is the pharmacological gold standard for assessing Leydig cell reserve and testicular steroidogenic capacity in rodent and primate models.
PeptidesFromChina.co supplies research-grade HCG as lyophilized powder, purity-verified by HPLC and bioactivity-assessed by international unit (IU) calibration against the WHO reference standard. Certificates of Analysis per batch. Wholesale quantities on request. For laboratory research use only.
| Chemical Class | Glycoprotein Gonadotropin / LH Receptor Agonist |
|---|---|
| CAS Number | 9002-61-3 |
| Molecular Weight | ~37,900 Da (with glycosylation; protein backbone ~23,500 Da) |
| Alpha Subunit | 92 amino acids (shared with LH, FSH, TSH) |
| Beta Subunit | 145 amino acids (HCG-specific; responsible for LHCGR binding) |
| Receptor Target | LHCGR (LH/CG receptor) — Gs/cAMP/PKA signalling |
| Half-life (research) | ~24–36 h (vs. ~1 h for native LH) |
| Activity Measurement | International Units (IU) per ampoule/vial (WHO reference) |
| Storage | -20°C lyophilized; 4°C reconstituted (up to 7 days) |
| Molecular Formula | N/A — glycoprotein (α/β heterodimer); see COA |
| Sequence | N/A — glycoprotein (see α and β subunit sequences in literature) |
| Name | Strength | Pack Size | Purity | Availability | Price (USD) |
|---|---|---|---|---|---|
| HCG | 5000 IU | 10 vials | ≥98% | In Stock | $88.00 |
| HCG | 10000 IU | 10 vials | ≥98% | In Stock | $175.00 |
Testing method: HPLC / LC-MS (["HPLC","LC-MS","Endotoxins","Sterility"]). Every batch is tested before shipment. Purity ≥99% confirmed per batch.
Certificate of Analysis: Simple COA. Documentation is available for every batch sold.
LHCGR is a G-protein coupled receptor (Gs class) expressed on Leydig cells in the testis and granulosa/luteal cells in the ovary. HCG binding activates adenylyl cyclase, elevating cAMP and activating PKA, which drives cholesterol mobilisation to mitochondria via StAR protein and subsequent steroidogenesis through CYP11A1, CYP17A1, and HSD17B pathways. Primary Leydig cell cultures and MLTC-1 or TM3 Leydig cell lines are standard in vitro formats for characterising HCG-stimulated testosterone production (RIA or ELISA) and cAMP accumulation. LHCGR expression level, receptor desensitisation kinetics, and beta-arrestin recruitment are characterised alongside testosterone output.
The HCG stimulation test is a pharmacological probe for Leydig cell steroidogenic reserve in rodent models. A single injection of HCG (10–100 IU in rats; 25–250 IU in primates) produces a testosterone peak at 2–6 hours that reflects LHCGR number, coupling efficiency, and steroidogenic enzyme capacity. In models of HPG axis suppression (GnRH agonist treatment, androgen suppression, orchiectomy), the HCG stimulation test characterises testicular reserve recovery. In hypogonadotropic hypogonadism models (GnRH receptor knockout mice), HCG bypasses the pituitary and directly stimulates testicular testosterone — allowing dissection of gonadotropin-independent testicular function.
In female rodent superovulation protocols, HCG is administered 48 hours after PMSG (equine chorionic gonadotropin) priming to trigger the LH surge and induce ovulation — the standard protocol for generating metaphase II oocytes for IVF research. LHCGR on granulosa cells mediates luteinisation (conversion to progesterone-secreting luteal cells) and oocyte maturation resumption. Granulosa cell models use HCG to characterise progesterone synthesis, cumulus expansion (hyaluronic acid secretion), and EGF receptor pathway activation, which mediates oocyte maturation signals downstream of the LH/HCG surge.
Research into HPG axis recovery following GnRH agonist or antagonist treatment uses HCG to assess Leydig cell function independently of pituitary LH secretion. In rodent models of chemical castration (buserelin, leuprolide), serial HCG stimulation tests document the timeline of testicular steroidogenic recovery as Leydig cell LHCGR expression normalises. These models are relevant to the broader field of HPG axis pharmacology including research into gonadorelin, kisspeptin-10, and GnRH antagonist reversal — all of which rely on intact Leydig cell responsiveness to gonadotropin stimulation as the functional endpoint.
HCG and LH both bind the LHCGR with high affinity, but HCG has a substantially longer plasma half-life (~24–36 h vs. ~1 h for native LH) due to the additional sialic acid residues on the HCG beta subunit's O-linked oligosaccharide chains. This makes HCG the preferred LH receptor agonist for sustained receptor stimulation assays and in vivo protocols. Native LH requires frequent dosing to maintain receptor occupancy; HCG provides stable prolonged stimulation. Pharmacologically, they produce qualitatively identical signalling (Gs/cAMP/PKA) but differ in the duration of the response.
HCG activity is expressed in International Units (IU) calibrated against the WHO 5th International Reference Preparation for HCG. One IU is defined by a bioassay measuring uterine weight increase in immature female mice (the Cartland-Nelson method) or, in modern practice, by LHCGR-based bioassay or radioimmunoassay equivalence. Research preparations are typically expressed as IU/vial, and the protein mass per IU varies between preparations depending on glycosylation extent. Certificates of Analysis should specify IU content, source (recombinant or urinary), and protein concentration for accurate dosing in quantitative research designs.
Lyophilized HCG should be stored at -20°C, protected from light. Reconstitute with sterile bacteriostatic water or PBS. The glycoprotein structure of HCG is more susceptible to denaturation than synthetic peptides — avoid vigorous vortexing and repeated freeze-thaw cycles of reconstituted solution. Reconstituted HCG is stable at 4°C for up to 7 days. For in vitro cell culture assays, filter sterilise reconstituted HCG through a 0.22 μm syringe filter before adding to culture medium to prevent bacterial contamination.
Yes. HCG is available through PeptidesFromChina.co on a B2B wholesale basis. Pricing and minimum order quantities are provided on request after account verification. Contact us via the Request page or Contact form.
For laboratory research use only. Not for human or veterinary use. PeptidesFromChina.co is a B2B wholesale supplier operating under strict research-use-only terms. All products are sold exclusively for in vitro and preclinical research purposes.