How is HCG stored and reconstituted for research?

Lyophilized HCG is stored at -20 C, protected from light and moisture. It is reconstituted in sterile or bacteriostatic water (0.9% benzyl alcohol); once reconstituted, store at 2-8 C for up to about 28 days and avoid repeated freeze-thaw cycles.

HCG — Research Overview | Explicit Research

Q: Is HCG approved for human use?

FDA-approved prescription drug products containing human chorionic gonadotropin exist. However, the research-grade material supplied by Explicit Research is not one of those approved drug products; it is supplied for laboratory research use only and is not for human consumption.

Q: What is the molecular formula and sequence of HCG?

HCG is a glycoprotein hormone rather than a simple peptide and has no single defined amino-acid sequence listed. Molecular weight is approximately 36,700 g/mol (about 36.7 kDa), CAS 9002-61-3.

Q: What targets and model systems has HCG been studied in?

Published literature has examined HCG in relation to the LH/hCG receptor (LHCGR), cAMP and adenylate cyclase signaling, and Leydig cell steroidogenesis, using in vitro receptor-binding and steroidogenesis assays alongside clinical and translational reproductive-endocrine study contexts.

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Research Use Only. HCG is sold by Explicit Research exclusively for laboratory and research purposes. This article summarizes published preclinical and experimental literature. It is not medical advice and does not constitute a recommendation for human use. All compounds are for in vitro and animal research only.

All information below describes the compound's chemical identity, laboratory handling, and the published research literature. It describes molecular targets and results in laboratory and animal models only — not effects in humans — and is not evidence of any human benefit.

What Is HCG?

HCG (Human Chorionic Gonadotropin), commonly abbreviated hCG in research contexts, is a naturally occurring glycoprotein hormone with a molecular weight of approximately 36,700 g/mol (about 36.7 kDa), isolated from human placental tissue and also produced recombinantly for research use. Because it is a glycoprotein rather than a simple peptide, it is characterized in the literature by its bioactivity in International Units rather than by a single defined amino-acid sequence. It is identified by CAS number 9002-61-3.

It is supplied as a reference compound for in vitro and animal research use only. The sections below summarize its chemical identity, laboratory handling, the molecular targets and model systems examined in the published literature, and the primary references — without describing outcomes, efficacy, or effects in humans.

Research Targets & Pathways

Published literature has examined HCG in relation to several molecular systems. These are pathway associations reported in laboratory and translational models; refer to the cited studies for methods and findings.

LH/hCG receptor (LHCGR) — examined in relation to gonadotropin receptor binding in reproductive-endocrine model systems.
cAMP / adenylate cyclase signaling — examined in relation to receptor-coupled second-messenger activation.
Leydig cell steroidogenesis pathway — examined in relation to steroidogenic signaling in gonadal cells.
Steroidogenic enzyme pathway — examined in relation to the enzymatic pathway from cholesterol to steroid hormones.
Hypothalamic–pituitary–gonadal (HPG) axis — examined in relation to gonadotropic and reproductive endocrine signaling.

Model Systems Studied

HCG has been used as a reference compound across a range of published model systems, spanning in vitro cell assays and clinical/translational study contexts. Refer to the cited literature for study designs, endpoints, and findings.

In vitro — Leydig cells — rat Leydig cell steroidogenesis assays.
In vitro — receptor pharmacology — LH/hCG receptor binding and adenylate cyclase / cAMP stimulation assays in human testis preparations.
Male reproductive contexts — hypogonadotropic hypogonadism and azoospermia study protocols noted in the literature.
Female reproductive contexts — ovarian stimulation and oocyte maturation study contexts.
Safety & research context — reproductive-endocrine monitoring and limitation literature.

Note: human chorionic gonadotropin is the active constituent of approved prescription drug products, and much of the cited literature is clinical and translational rather than purely preclinical; the citations are organized by mechanism and assay system in the source material.

Molecular & Technical Profile

Glycoprotein hormone | MW ~36,700 g/mol (~36.7 kDa) | CAS 9002-61-3 | No single defined amino-acid sequence (glycoprotein)

Storage, Reconstitution & Working Concentrations

Lyophilized storage−20°C, protected from light and moisture; reported stable up to ~24 months when stored correctly; confirm expiry on lot-specific COA

Reconstituted storage2–8°C up to ~28 days; avoid repeated freeze–thaw cycles; single-use aliquots recommended for extended studies

SolubilityFreely soluble in sterile water for injection or bacteriostatic water (0.9% benzyl alcohol); also soluble in PBS (pH 7.4); avoid organic solvents such as DMSO

ReconstitutionBring vial to room temperature (~15–30 min); add solvent slowly down the inner wall — not directly onto the lyophilized cake; swirl gently, do not vortex; if turbidity persists, rest at 2–8°C ~10 min and swirl again

Stock solutionTypically 1 mg/mL in sterile bacteriostatic water; further dilutions in PBS (pH 7.4) or serum-free culture medium immediately before use

In vitro working range1–100 IU/mL (~0.01–1 µg/mL) in Leydig cell steroidogenesis assays and LH receptor binding / cAMP stimulation assays; confirm optimal concentration via dose-response

Animal model dosingSee cited literature for model-specific concentration ranges and administration protocols

Endotoxin<1 EU/mg (LAL assay); confirm lot-specific COA before use in sensitive cell systems

Storage, reconstitution, and working-concentration values are general laboratory guidance for in vitro and animal research; always confirm against the lot-specific Certificate of Analysis.

Current Research Status

Human chorionic gonadotropin is the active constituent of FDA-approved prescription drug products, and much of the published literature is clinical and translational rather than purely preclinical. The research-grade material supplied by Explicit Research is not one of those approved drug products; it is a reference compound for laboratory research use only and is not for human consumption. The sections above describe the receptors, signaling pathways, and model systems examined in the cited literature and do not describe outcomes in humans. Ongoing research continues to characterize the compound's mechanistic profile in receptor-binding and steroidogenesis assay systems.

Research FAQ

Is HCG approved for human use?

FDA-approved prescription drug products containing human chorionic gonadotropin exist. However, the research-grade material supplied by Explicit Research is not one of those approved drug products — it is supplied for laboratory research use only and is not for human consumption.

What is HCG's molecular formula and sequence?

HCG is a glycoprotein hormone rather than a simple peptide and has no single defined amino-acid sequence listed — molecular weight approximately 36,700 g/mol (~36.7 kDa), CAS 9002-61-3.

How is HCG stored and reconstituted?

Store lyophilized at −20°C, protected from light and moisture. Reconstitute in sterile or bacteriostatic water; store the reconstituted solution at 2–8°C for up to ~28 days and avoid repeated freeze–thaw cycles.

What targets and model systems has HCG been studied in?