Hormones & Fertility
HCG
Human Chorionic Gonadotropin · Pregnyl · Novarel
What it is
HCG is a glycoprotein hormone normally produced during pregnancy by the placenta. It mimics LH (luteinizing hormone) almost exactly. FDA-approved for fertility treatment, hypogonadism, and a few other indications. Standard companion to TRT to maintain testicular function and fertility.
How it works
Binds LH receptors on Leydig cells in the testes, stimulating them to produce testosterone and maintaining their size and function. On TRT, the body's own LH production shuts down, causing testicular shrinkage and infertility — HCG bypasses this by directly providing the LH signal.
Benefits
- Maintains testicular size on TRT
- Preserves fertility on TRT
- Restores natural testosterone production after steroid cycles
- Can rescue secondary hypogonadism (pituitary dysfunction)
- Useful in PCT (post-cycle therapy) protocols
Timeline
- Day 1–3
- Testosterone surge.
- Week 1–2
- Testicular size restoration begins.
- Month 1–3
- Fertility recovery (sperm count over 3 months).
Dosing & titration
TRT companion250–500 IU subQ, 2–3x per week
PCT (post-steroid)500–1500 IU every other day for 2–4 weeks
Fertility1500–5000 IU 2–3x per week (with FSH if needed)
When to titrate upHigher doses (above 1000 IU regularly) downregulate LH receptors and aromatize estrogen heavily. Stay low for maintenance.
Side effects & risks
- Estrogen rise (HCG strongly stimulates aromatase)
- Water retention
- Acne
- Mood changes
- Possible Leydig cell desensitization at high chronic doses
- Gynecomastia risk if estrogen isn't managed
Get baseline estradiol and monitor. HCG raises estrogen more than testosterone alone. Many users add an aromatase inhibitor at higher doses.
Typical price
$80–$200/mo10,000 IU vial from a 503A compounding pharmacy. Branded Pregnyl/Novarel can be $200–$500.
Studies
- Coviello AD et al. Low-dose HCG maintains intratesticular testosterone in normal men with TRT-induced gonadotropin suppression — Established the LH-mimicking protocol. PubMedJCEM, 2005
- Search PubMed for HCG TRT — PubMed searchLive PubMed search
Educational reference only. Not medical advice.