Melanocortin MC3R/MC4R Research Guide

HCG: Mechanism, Handling & Research Guide

Also known as: human chorionic gonadotropin, hcg peptide, hcg 5000iu, hcg 10000iu, choriogonadotropin, CG, chorionic gonadotrophin

Key Facts

HCG is a melanocortin mc3r/mc4r research peptide. Human chorionic gonadotropin (hCG) is a glycoprotein hormone studied for its luteinizing-hormone-like activity on gonadal tissue. For laboratory research use only. It is supplied as a lyophilized powder for laboratory and in-vitro research use only — not for human consumption.

Classification	Glycoprotein gonadotropin (LH/CG receptor agonist)
CAS Number	9002-61-3
Research Half-Life	Biphasic; approximately 6-12 hours initial and ~24-36 hours terminal in published human pharmacokinetic studies (long-acting relative to LH)
Form	Lyophilized powder
Research Category	Melanocortin MC3R/MC4R

What is HCG?

Human chorionic gonadotropin is a glycoprotein hormone that mimics luteinizing hormone by binding the LH/hCG receptor on Leydig and granulosa cells. In research settings it is used as a tool to study steroidogenesis, gonadal function, and the hypothalamic-pituitary-gonadal axis, including models of testosterone production and ovulation induction pathways. Because of its long half-life and potent receptor activity, it is a common reference agonist in reproductive endocrinology research. Supplied as a lyophilized powder for in-vitro and laboratory research use only; not for human or veterinary use.

HCG Research Applications

In published and preclinical research, HCG has been studied across the following areas:

LH/hCG receptor signaling research
Steroidogenesis and gonadal function studies
Reproductive endocrinology models
HPG-axis research

HCG in Research: Study Context

Published literature characterizes human chorionic gonadotropin as a heterodimeric glycoprotein hormone sharing a common alpha-subunit with LH, FSH and TSH and a hormone-specific beta-subunit, acting as an agonist at the LH/CG receptor (LHCGR) on Leydig and granulosa cells to drive Gs/cAMP-mediated steroidogenesis (Cole 2010; Riccetti et al. 2017). It is widely used in reproductive-endocrinology research as a reference LHCGR agonist to study steroidogenic signaling and gonadal function, with reports of biased agonism relative to LH at the same receptor. For laboratory research use only; this material is not FDA-approved and no human concentration is provided. For in-vitro work, lyophilized material is reconstituted with bacteriostatic water to a defined mg/mL (or IU/mL) concentration, and investigators should reference the primary literature and the lot-specific Certificate of Analysis (COA).

How HCG Compares

Researchers frequently evaluate HCG alongside related compounds:

HCG vs PT-141 — A melanocortin-receptor agonist studied in sexual-wellness contexts via central nervous system pathways, mechanistically unrelated to hCG's direct gonadal steroidogenic signaling.

HCG — Frequently Asked Questions

What receptor does hCG act on in research models?

Published work characterizes hCG as an agonist at the LH/CG receptor (LHCGR), a class A G-protein-coupled receptor expressed on Leydig and granulosa cells. Receptor activation couples primarily to Gs/adenylyl cyclase, raising intracellular cAMP and driving steroidogenic gene expression. Because hCG and LH share this receptor, hCG is frequently used as a reference LHCGR agonist in in-vitro signaling studies (Riccetti et al. 2017).

How does hCG differ from luteinizing hormone in the literature?

hCG and LH bind the same LHCGR but differ in their beta-subunits and glycosylation, which the literature links to a longer circulating half-life for hCG and to differential, or biased, downstream signaling. Riccetti et al. (2017) reported that hCG and LH preferentially engage distinct signaling cascades at the LH/CG receptor despite producing comparable steroidogenic output, a distinction relevant to receptor-pharmacology research.

What is hCG used to study in reproductive endocrinology research?

In research settings it serves as a tool to probe steroidogenesis, LHCGR signaling, and gonadal function within hypothalamic-pituitary-gonadal axis models. Reviews such as Cole (2010) catalog the biochemistry of hCG and related molecules. These are mechanistic and biochemical research applications; no therapeutic or human-use claim is made.

How is hCG handled for laboratory research use?

Supplied as a lyophilized powder for in-vitro and laboratory research use only, it is reconstituted with bacteriostatic water to a defined concentration (mg/mL or IU/mL) chosen by the investigator for the assay. Store lyophilized material at -20C and reconstituted solution at 2-8C. Confirm identity and purity against the lot-specific COA; it is not FDA-approved and not for human or veterinary use.

Is HCG legal to buy for research?

HCG is sold in the United States as a research chemical for laboratory and in-vitro use only. It is not approved by the FDA for human use and is not sold for human consumption. Researchers are responsible for compliance with all applicable federal, state, and institutional regulations.

Does HCG come with a Certificate of Analysis?

Yes. Every batch of HCG from Elyte Peptides ships with a third-party Certificate of Analysis (COA) documenting identity and HPLC purity (≥98%), so research results can be traced to a verified lot.

What is HCG?

Human chorionic gonadotropin (hCG) is a glycoprotein hormone studied for its luteinizing-hormone-like activity on gonadal tissue. For laboratory research use only. It is supplied in 10,000 IU vials and intended strictly for in-vitro and laboratory research use only.

How should HCG be stored?

HCG should be stored at -20°C for long-term storage or 2-8°C for short-term use. Keep the vial sealed and protected from light, moisture, and repeated freeze-thaw cycles. Once reconstituted, store at 2-8°C and use within 30 days.

What purity is HCG?

HCG is manufactured to a minimum purity of ≥98% as verified by HPLC analysis, with identity confirmed by mass spectrometry. Each batch ships with a Certificate of Analysis (COA).

Research References

All research guides