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Peptide Library / Hormone / Fertility

HCG

Human Chorionic Gonadotropin

HCG (Human Chorionic Gonadotropin) Research Protocol

Complete Research Guide 4 min read1 peer-reviewed references

Quickstart Overview

HCG is a glycoprotein hormone that mimics luteinizing hormone (LH) at its receptor. In men it directly stimulates testicular Leydig cells to produce testosterone and maintain testicular size and fertility — the basis of its use alongside testosterone therapy and in fertility research.

Reconstitution
Add bacteriostatic water per vial IU; e.g. 5,000 IU + 5 mL → 1,000 IU/mL
TRT Range
250–500 IU 2–3× weekly
Measuring Reference
At 1,000 IU/mL: 500 IU = 0.5 mL = 50 units
Frequency
2–3× weekly
Route (studies)
Subcutaneous
Target
LH receptor

Scientific Data

Molecular Formula
—
Molecular Weight
—
Sequence
α/β glycoprotein
Sequence Length
14
CAS
Research compound
Peptide Family
Glycoprotein hormone
Half-life
Refer to published literature
Solubility
Bacteriostatic water, sterile saline
Storage
Lyophilized: -20°C. Reconstituted: 2–8°C, use within 2–4 weeks.
Appearance
White lyophilized powder
Standard: 0 mg vial · 5 mL diluent

Dosing & Reconstitution Guide

Interactive Reconstitution
Adjust vial size, diluent and target dose. Results update live.
Full Precision Calculator →
Concentration
2.00 mg/mL
Draw Volume
0.250 mL
Syringe Units
25.0 U
Doses / Vial
20

Units assume a U-100 insulin syringe (100 units = 1 mL). Dosed in IU, not mg. Reconstitute per the vial's IU and refrigerate.

Frequency: 2–3× weekly

Reconstitution Steps

  1. 1Allow the lyophilized vial and bacteriostatic water to reach room temperature (~15 min).
  2. 2Swab both vial stoppers with a fresh 70% isopropyl alcohol pad and let them dry.
  3. 3Draw 5.0 mL of bacteriostatic water into a mixing syringe.
  4. 4Insert at an angle and let the water run slowly down the glass wall — never directly onto the powder.
  5. 5Gently swirl (do not shake) until the solution is completely clear.
  6. 6Label with date and concentration (mg/mL) and refrigerate at 2–8 °C immediately.

Supplies Needed

Planning example for a 8-week protocol at approximately 500 mcg per day.

Peptide (0 mg vials)
Estimate vials from total mass: 500 mcg/day × 56 days.
Bacteriostatic Water
One 10–30 mL vial typically covers a full cycle.
Insulin Syringes (U-100)
One per administration (29–31 G, 0.3–0.5 mL).
Alcohol Swabs
Two per administration (vial + site).
Sharps Container
Required for safe disposal.

Protocol Overview

Goal
Model LH-receptor testicular stimulation.
Schedule
2–3× weekly, ongoing.
Dose Range
250–500 IU (TRT) to 10,000 IU (trigger).

Dosing Protocol

TRT support
250–500 IU 2–3× weekly
Fertility/restart
Higher doses per protocol
Ovulation trigger
5,000–10,000 IU single dose (fertility)
Cycle Length
Ongoing with TRT or protocol-based
Timing
2–3× weekly for maintenance
Route
Subcutaneous

Storage Instructions

Lyophilized
−20 °C long term (18–24 months); stable at room temperature for short transit.
Reconstituted
2–8 °C refrigerated; use within 4 weeks.
Light
Protect from direct light; keep in the original carton.
Freeze/Thaw
Avoid repeat freeze–thaw cycles after reconstitution.

Important Notes

  • Dosed in international units (IU), not milligrams.
  • Monitor oestrogen — HCG can increase aromatisation.

How This Works

HCG binds the LH/HCG receptor on testicular Leydig cells (and ovarian cells), driving testosterone synthesis and, with FSH support, spermatogenesis. Because it acts directly at the gonad (downstream of the pituitary), it maintains testicular function even when the HPG axis is suppressed by exogenous testosterone — preventing the atrophy and infertility that otherwise accompany TRT. It is also used to trigger ovulation in fertility protocols.

Potential Benefits & Side Effects

Reported in research
  • Direct stimulation of testicular testosterone production
  • Maintenance of testicular size and fertility on TRT
  • Ovulation trigger in fertility protocols
  • Restoration of function after HPG suppression
Possible considerations
  • Injection-site reactions
  • Possible oestrogen rise (aromatisation) → monitor
  • Gynecomastia or water retention at higher doses
  • Acne or mood changes

Lifestyle Factors

  • Adequate hydration and 7–9 h of sleep are standard controls in most research protocols.
  • Consistent dose timing improves the reliability of any self-tracked endpoints.
  • Maintain a clean, sterile workflow for every draw to avoid contamination.

Injection Technique

  1. 1Wash hands, then prep the vial top and the target site with separate alcohol swabs.
  2. 2Pinch a subcutaneous skin fold (abdomen, ~2 inches from the navel) and insert at 45–90°.
  3. 3Depress the plunger slowly over 3–5 seconds, hold 5 seconds, then withdraw.
  4. 4Rotate sites each administration and dispose of the syringe in a sharps container.

Frequently Asked Questions

Third-party HPLC testing

CG Labz Verified Batches

No published batches yet.

Research Disclaimer

All compounds are supplied strictly for laboratory research. Dosing figures below summarize ranges reported in published preclinical and clinical literature for reference purposes only. CG Labz does not provide medical advice or individualized dosing recommendations.

Peer-reviewed literature

References

  1. [1] Journal of Clinical Endocrinology & Metabolism
    Coviello A.D. et al. Low-dose HCG maintains intratesticular testosterone.
    View Source