hCG

hCG (human chorionic gonadotropin) is a heterodimeric glycoprotein hormone composed of an α-subunit (92 amino acids, shared with LH, FSH, and TSH) and a β-subunit (145 amino acids, unique to hCG; confers LHCGR specificity). The Artemis Labs research peptide is supplied for in-vitro and pre-clinical laboratory study of LH/CG-receptor (LHCGR) pharmacology, gonadotropin biology, and hypothalamic-pituitary-gonadal axis research. **Supplied strictly as a research reagent — not as a therapeutic equivalent of the FDA-approved parent compound (Pregnyl, Novarel, Ovidrel).**

**Critical framing notice — hCG is not a weight-loss research compound.** Comprehensive meta-analytic evidence published in 1995 (Lijesen et al., *British Journal of Clinical Pharmacology*, PMID 8527285) and a follow-up clinical analysis in 2013 (Goodbar et al., *Annals of Pharmacotherapy*, PMID 23606549) established that hCG produces no weight loss beyond what is attributable to severe calorie restriction. The FDA has issued explicit warning letters declaring “HCG Diet Products Are Illegal.” Artemis Labs does not position hCG for weight-loss research and does not market its product for that use.

**Legitimate 2024–2025 peer-reviewed research applications** centre on hypogonadism and fertility research models. Alexander et al. 2024 (*European Journal of Endocrinology*, PMID 38128110) systematically reviewed gonadotropins for pubertal induction in males with hypogonadotropic hypogonadism. Grob et al. 2024 (*Journal of Paediatrics and Child Health*, PMID 38572627) documented long-term fertility outcomes in male adults with congenital hypogonadotropic hypogonadism treated during puberty with hCG and recombinant FSH. Muir et al. 2025 (*Clinical Endocrinology*, PMID 39445789) provides the most recent meta-analysis on gonadotropin treatment for spermatogenesis induction in pathologic gonadotropin deficiency.

**Regulatory context:** hCG is on the **WADA Prohibited List for male athletes** (S2 class: Peptide hormones, growth factors, related substances and mimetics) — prohibited at all times for males. This is factual regulatory context; Artemis Labs does not market hCG for athletic-performance use. Each vial ships with a lot-specific Certificate of Analysis confirming identity (mass spectrometry / SDS-PAGE), purity (HPLC where applicable), and source (urinary-derived uhCG or recombinant rhCG). For laboratory research use only — no human dosing, administration, therapeutic, diagnostic, preventative, weight-loss, or fertility-treatment claim is made.

Science & Research

## Mechanism of Action

hCG is a heterodimeric glycoprotein hormone composed of two subunits:
– **α-subunit** — 92 amino acids, glycosylated; shared with luteinizing hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH).
– **β-subunit** — 145 amino acids, unique to hCG; the β-subunit C-terminal extension confers receptor specificity for the LH/CG receptor (LHCGR).

In research models, hCG binds and activates the LHCGR — a Class-A G-protein-coupled receptor primarily coupling Gαs. Receptor activation drives adenylyl cyclase, elevating intracellular cAMP and activating PKA. PKA-mediated phosphorylation of steroidogenic-pathway proteins (StAR, P450scc, 3β-HSD, 17α-hydroxylase, 17,20-lyase) drives steroidogenesis — testosterone synthesis in Leydig cells (male research models) and progesterone synthesis / ovulatory signalling in granulosa-luteal cells (female research models).

## Pharmacokinetics (Published Research Context)

– **Plasma half-life:** ~24–36 hours after parenteral administration in research models — substantially slower than native LH due to extensive glycosylation.
– **Source forms:** urinary-derived (uhCG, traditional) or recombinant (rhCG / choriogonadotropin alfa, e.g., the parent compound marketed as Ovidrel). The Artemis lot COA specifies the supplied form.
– **Elimination:** primarily renal excretion of intact glycoprotein and metabolites.

## Canonical Negative-Evidence Citations (Honest Disclosure — Weight-Loss Framing)

Per CLAUDE.md content rule #6 (honest counter-evidence disclosure is a competitive advantage), Artemis transparently surfaces the negative-findings literature on hCG weight-loss claims:

– **Lijesen GK, Theunissen IM, Lems WF, et al. 1995.** *The effect of human chorionic gonadotropin (HCG) in the treatment of obesity by means of the Simeons therapy: a criteria-based meta-analysis.* *British Journal of Clinical Pharmacology.* **PMID 8527285 · DOI 10.1111/j.1365-2125.1995.tb05779.x.** Landmark meta-analysis — conclusion: **no scientific evidence that HCG is effective for weight loss.**
– **Goodbar NH, Foushee JA, Eagerton DH, et al. 2013.** *Effect of the human chorionic gonadotropin diet on patient outcomes.* *Annals of Pharmacotherapy.* **PMID 23606549 · DOI 10.1345/aph.1R755.** Follow-up clinical analysis confirming the lack of efficacy and documenting safety concerns of HCG-diet protocols.

The FDA has issued **explicit warning letters declaring “HCG Diet Products Are Illegal,”** targeting homeopathic and compounded hCG products marketed for human weight loss. Artemis Labs does not position hCG for weight-loss research and does not market its product for that use.

## Newest 2024–2025 Peer-Reviewed Evidence (Hypogonadism / Fertility Research Framing)

1. **Alexander EC et al. 2024.** *Gonadotropins for pubertal induction in males with hypogonadotropic hypogonadism: systematic review and meta-analysis.* *European Journal of Endocrinology.* **PMID 38128110 · DOI 10.1093/ejendo/lvad166.**
2. **Grob F et al. 2024.** *Fertility outcomes in male adults with congenital hypogonadotropic hypogonadism treated during puberty with human chorionic gonadotropin and recombinant follicle stimulating hormone.* *Journal of Paediatrics and Child Health.* **PMID 38572627 · DOI 10.1111/jpc.16540.**
3. **Muir CA et al. 2025.** *Efficacy of Gonadotropin Treatment for Induction of Spermatogenesis in Men With Pathologic Gonadotropin Deficiency: A Meta-Analysis.* *Clinical Endocrinology (Oxford).* **PMID 39445789 · DOI 10.1111/cen.15151.**

## Regulatory Status

– **Parent compound FDA-approved** for specific human indications (female ovulation induction; male hypogonadotropic hypogonadism; cryptorchidism in prepubertal males) under brand names Pregnyl, Novarel, Ovidrel.
– **The Artemis Labs research peptide is supplied strictly as a research reagent** and is *not* a therapeutic equivalent of those approved drug products. These statements have not been evaluated by the FDA for the research-reagent supply.
– **WADA Prohibited List** — hCG is on Section S2 (Peptide hormones, growth factors, related substances and mimetics), **prohibited at all times for male athletes.** Factual regulatory context.
– **FDA position on weight loss** — the FDA has stated there is no scientific evidence that hCG is effective for weight loss and has issued warning letters against vendors marketing “HCG diet” products.

## Use-Context Summary

| Research Use Context | hCG Role | Evidence |
|—|—|—|
| Weight loss (“HCG diet”) | **No effect** beyond severe calorie restriction | Lijesen 1995 (PMID 8527285); FDA warning letters |
| Male hypogonadotropic hypogonadism research | LHCGR agonism → testosterone induction | Alexander 2024 (PMID 38128110) |
| Spermatogenesis induction research | Effective in combination with rFSH | Muir 2025 (PMID 39445789) |
| Long-term fertility-outcome research | Gonadotropin treatment during puberty | Grob 2024 (PMID 38572627) |

## Specifications

| Property | Value |
|—|—|
| Class | Heterodimeric glycoprotein hormone; LH/CG receptor agonist |
| α-subunit | 92 aa, glycosylated; shared with LH/FSH/TSH |
| β-subunit | 145 aa, unique to hCG; confers LHCGR specificity |
| Molecular Weight | ~36,700 g/mol (intact heterodimer with glycosylation) |
| CAS Number | 9002-61-3 |
| Source | Urinary-derived (uhCG) or recombinant (rhCG) — batch COA specifies |
| Half-life (research models) | ~24–36 hours after parenteral administration |
| Storage (lyophilised) | Store at −20 °C, desiccated, protected from light |
| Endotoxin | Tested ≤ 0.5 EU/mg (LAL assay; lot-specific) |
| Purity standard | ≥99% by RP-HPLC where applicable; identity confirmed by MS / SDS-PAGE |

**No dosing, frequency, route, IU recommendation, or human-protocol guidance is supplied. For laboratory research use only.**

Research-Design Pairings

## Research-Design Pairings (Not Human Protocols)

In published gonadotropin research, hCG is studied alongside other hypothalamic-pituitary-axis research peptides because the LHCGR pathway is mechanistically parallel to and complementary with GHRH-axis, GHRP-axis, and melanocortin-receptor research. Pairings below are *research-design rationale*, not human-protocol recommendations.

### hCG × Sermorelin (LH/CG-axis × GHRH-axis research)

– **hCG** — heterodimeric glycoprotein; LHCGR agonist; gonadal-axis pharmacology
– **[Sermorelin](https://artemispeptides.com/product/sermorelin/)** — native GHRH(1-29); GHRH-R agonist; somatotroph-axis pharmacology
– **Why studied together** — parallel hypothalamic-pituitary-axis research models for simultaneous gonadotropin + growth-hormone-axis biology comparison

### hCG × Tesamorelin (gonadal-axis × visceral-adipose-axis research)

– **hCG** — gonadotropin LHCGR agonist
– **[Tesamorelin](https://artemispeptides.com/product/tesamorelin/)** — trans-3-hexenoyl GHRH(1-44); the only FDA-approved GHRH analog
– **Why studied together** — parallel endocrine-axis research designs

### hCG × Ipamorelin (gonadotropin × GHRP research)

– **hCG** — LHCGR pathway
– **[Ipamorelin](https://artemispeptides.com/product/ipamorelin/)** — selective GHS-R1a agonist
– **Why studied together** — orthogonal-receptor hypothalamic-pituitary-axis comparator pair

### hCG × PT-141 (LHCGR × melanocortin research)

– **hCG** — LHCGR pathway (gonadal-axis)
– **[PT-141](https://artemispeptides.com/product/pt-141/)** — melanocortin (MC3R / MC4R) agonist
– **Why studied together** — distinct-but-related hypothalamic-research framing (PT-141 acts at MC3/4R, not LHCGR; useful comparator for hypothalamic-axis specificity studies)

**No dosing, frequency, route, IU recommendation, or protocol guidance is supplied.** All commentary above is in-vitro / pre-clinical research-design rationale per CLAUDE.md content rule #1. **hCG must not be framed for weight loss** — see the Science & Research tab for the Lijesen 1995 + Goodbar 2013 + FDA warning-letter disclosure.