HCG (Human Chorionic Gonadotropin)

Human Chorionic Gonadotropin (HCG) is a glycoprotein hormone naturally produced by the placenta during pregnancy. It consists of two subunits: an alpha subunit identical to other pituitary hormones (LH, FSH, TSH) and a unique beta subunit that confers HCG's specific biological activity. Pharmaceutical HCG is derived from the urine of pregnant women or produced recombinantly. It binds to and activates LH receptors, making it valuable for treating hypogonadism, infertility, and cryptorchidism. In TRT protocols, HCG is commonly used to maintain testicular function, preserve fertility, and prevent testicular atrophy.

• Hypogonadotropic Hypogonadism
• Testosterone Support
• Fertility Preservation

Maintains testicular function during TRT, preserves fertility, prevents testicular atrophy, stimulates endogenous testosterone production, induces ovulation in women, treats cryptorchidism in children

HCG binds to LH receptors on Leydig cells in the testes, stimulating testosterone and estrogen biosynthesis. In women, it acts on ovarian theca cells to stimulate progesterone production and triggers final oocyte maturation. Half-life is approximately 24-36 hours with peak levels 6-12 hours post-injection. Bioavailability is 40-50% via subcutaneous or intramuscular routes.

Peak plasma concentration: 6 hrs. Elimination half-life: 1.5 days. Largely cleared by: ~7.5 days.

Research protocols from published literature — not dosing recommendations.

• Testosterone — Synergistic - Common Combination: HCG is frequently used alongside TRT to maintain testicular function, preserve fertility, and prevent atrophy. Standard TRT protocol: 250-500 IU HCG twice weekly
• Clomiphene (Clomid) — Use Sequentially: Both stimulate testosterone production via different mechanisms. Sometimes used sequentially in PCT protocols. Generally not combined simultaneously - choose one approach
• Aromatase Inhibitors — Commonly Combined: HCG increases intratesticular aromatase activity and may elevate estrogen. AIs like anastrozole are often used concurrently to manage estrogen levels during TRT+HCG protocols
• GnRH Analogs — Monitor Combination: GnRH agonists/antagonists suppress LH. HCG may be used to maintain testicular function during GnRH analog therapy or for recovery afterward. Timing coordination required
• FSH (Follitropin) — Synergistic for Fertility: Combined HCG + FSH therapy is standard for male infertility treatment in hypogonadotropic hypogonadism, achieving spermatogenesis in 70-90% of patients
• Kisspeptin — Complementary Mechanisms: Both stimulate the HPG axis via different mechanisms. Kisspeptin acts upstream at the hypothalamus while HCG acts directly on gonads. Potentially synergistic for fertility restoration
• Thyroid Hormones — Monitor Required: High-dose HCG has weak TSH-like activity due to alpha subunit homology. Can cause transient hyperthyroidism with very high HCG levels (pregnancy, tumors). Monitor thyroid function
• Metformin — Protective Combination: In women with PCOS undergoing ovulation induction, metformin may reduce ovarian hyperstimulation syndrome risk when combined with HCG. Often used together in fertility protocols

Supplies:

• HCG lyophilized powder vial (5,000 or 10,000 IU typical)
• Bacteriostatic water or sodium chloride diluent (provided)
• Insulin syringes (29-31 gauge) for SubQ or larger for IM
• Alcohol prep pads
• Sterile work surface
• Refrigerator for storage (2-8°C)

1. 1Remove HCG vial and diluent from packaging
2. 2Clean the rubber stoppers of both vials with alcohol swabs
3. 3Draw the diluent (typically 1-2 mL provided) into syringe
4. 4Slowly inject diluent into HCG vial, aiming at the vial wall
5. 5Gently swirl to dissolve - do not shake vigorously
6. 6Allow to sit until completely dissolved and solution is clear
7. 7Calculate concentration: e.g., 5000 IU in 2 mL = 2500 IU/mL
8. 8Label vial with reconstitution date and concentration
9. 9Store reconstituted HCG in refrigerator at 2-8°C
10. 10Use within 30-60 days (depending on diluent and product)

Day 1-3: No immediate noticeable effects; HCG is working at cellular level. Week 1-2: Testosterone increase detectable on labs; possible improved mood/energy if previously deficient. Week 2-4: Testicular fullness/size improvement noticeable; improved sense of well-being. Week 4-8: Stable testosterone levels; fertility parameters beginning to improve. Month 2-3: Sperm count improvements if used for fertility; sustained testicular function. Long-term: Maintained testicular size and function with ongoing use; fertility preserved. Note: Effects depend heavily on context (TRT adjunct vs monotherapy vs fertility protocol).

FDA-approved for specific indications - discuss off-label use with physician. May cause or worsen gynecomastia due to increased estrogen - monitor and manage with AI if needed. High doses can cause excessive testosterone and estrogen - start low, titrate based on labs. Can cause headaches, irritability, and mood swings, especially initially. Risk of ovarian hyperstimulation syndrome (OHSS) in women - requires careful monitoring. Contraindicated in hormone-sensitive cancers (prostate, breast). Antibody formation possible with long-term use, potentially reducing efficacy. May cause fluid retention and edema. Precocious puberty risk in pediatric patients if used inappropriately. Thromboembolism risk may be elevated - caution in patients with history of clots.

FDA-approved for specific indications - discuss off-label use with physician. May cause or worsen gynecomastia due to increased estrogen - monitor and manage with AI if needed. High doses can cause excessive testosterone and estrogen - start low, titrate based on labs. Can cause headaches, irritability, and mood swings, especially initially. Risk of ovarian hyperstimulation syndrome (OHSS) in women - requires careful monitoring. Contraindicated in hormone-sensitive cancers (prostate, breast). Antibody formation possible with long-term use, potentially reducing efficacy. May cause fluid retention and edema. Precocious puberty risk in pediatric patients if used inappropriately. Thromboembolism risk may be elevated - caution in patients with history of clots.

HCG (Human Chorionic Gonadotropin) should be stored at Lyophilized: room temperature (some products) or refrigerated. Reconstituted: refrigerate 2-8°C, use within 30-60 days.