HCG
Also known as: Human Chorionic Gonadotropin, Pregnyl, Novarel, Ovidrel
Human Chorionic Gonadotropin | LH Receptor Agonist
Overview
HCG is a glycoprotein hormone naturally produced by the placenta during pregnancy that binds LH receptors to stimulate testosterone and estrogen biosynthesis. FDA-approved for cryptorchidism, hypogonadotropic hypogonadism, and ovulation induction.
Key benefits
- Maintains testicular function during TRT
- Preserves fertility and prevents testicular atrophy
- Stimulates endogenous testosterone production
- Induces ovulation in women
- FDA-approved for multiple indications
- Well-established safety profile
Mechanism of action
Binds to LH receptors on Leydig cells in testes, stimulating testosterone production with a half-life of 24-36 hours, peak levels 6-12 hours post-injection, and 40-50% bioavailability via SubQ or IM routes.
Molecular data
- Type
- Heterodimeric glycoprotein
- Half-life
- 24-36 hours
Indications
What the research community uses this compound for, with self-reported effectiveness.
Male Fertility
Female Fertility
Pediatric
Dosing protocols
Common protocols by delivery method. Adjust the curve below to model accumulation in your own cycle.
Delivery method
| Protocol | Dose | Frequency | Duration |
|---|---|---|---|
| — | 250-500 IU | Every other day | — |
| — | 500-1000 IU | Twice weekly | — |
| — | 1500-2000 IU | 2-3x weekly | — |
| — | 1500-2000 IU | 2-3x weekly | — |
| — | 1000-5000 IU | 2-3x weekly for 3-4 weeks | — |
| — | 5000-10,000 IU | Single dose | — |
| — | 1000-1500 IU | Every other day for 2-3 weeks | — |
Safety
Reported adverse effects, contraindications, and what to monitor on cycle.
Common side effects
- Gynecomastia (breast tenderness/swelling) due to increased estrogen
- Headaches, irritability, and mood swings (especially initially)
- Fluid retention and edema
- Potential antibody formation with long-term use
Contraindications
- Hormone-sensitive cancers (prostate, breast)
- Pregnancy (except as prescribed)
- Precocious puberty risk in children
Monitoring
- Monitor estrogen levels - may need aromatase inhibitor
- Regular testosterone and fertility panel
- Watch for gynecomastia signs
References
Primary literature and clinical-trial data informing this entry.
Featured in these stacks
- Female Fertility SupportAn educational ovulation-induction stack — gonadotropins (hMG + hCG) as used in assisted-reproduction protocols.2 compounds
- Male Fertility RestartA fertility-focused stack to stimulate the testicular axis — hCG with a SERM to support sperm production and natural testosterone.3 compounds