HCG (Human Chorionic Gonadotropin)

FDA Approved

Human Chorionic Gonadotropin | LH Receptor Agonist

Weight: 36,700 Da
Half-life: 24-36 hours
Chain: 237 amino acids (alpha: 92, beta: 145)
5 studies
2019 latest
2 recent
FDA Approved
Dose 250-1500 IU (lower for TRT adjunct, higher for fertility)
Frequency 2-3 times weekly, or every other day for lower doses
Cycle Ongoing with TRT or 3-6 months for fertility protocols
Storage Lyophilized: Room temperature. Reconstituted: 2-8°C, use within 30-60 days

Community Research

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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.

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.

01 Maintains testicular function during TRT
02 Preserves fertility and prevents testicular atrophy
03 Stimulates endogenous testosterone production
04 Induces ovulation in women
05 FDA-approved for multiple indications
06 Well-established safety profile

Molecular Data

Molecular Weight
36,700 Da
Chain Length
237 amino acids (alpha: 92, beta: 145)
Type
Heterodimeric glycoprotein
Peak 0.0 mcg
Trough 0.0 mcg
SS Peak 0.0 mcg
SS Trough 0.0 mcg

Research Indications

Male Fertility
TRT Adjunct most effective

Maintains intratesticular testosterone at baseline during testosterone therapy, preventing atrophy and preserving fertility.

Hypogonadotropic Hypogonadism most effective

FDA-approved for secondary hypogonadism; combined with FSH for spermatogenesis induction.

Post-Cycle Therapy effective

Restores testicular function after anabolic steroid cycles.

Female Fertility
Ovulation Induction most effective

FDA-approved trigger for follicular maturation; 15-25% pregnancy rate per cycle.

Pediatric
Cryptorchidism moderate

FDA-approved for prepubertal undescended testes not due to anatomical obstruction; ~25% success rate.

Dosing Protocols

Subcutaneous or intramuscular injection. Administer 2-3 times weekly, evenly spaced. For TRT, many inject HCG on days between testosterone injections.

GoalDoseFrequencyRoute
TRT Adjunct (Low)250-500 IUEvery other daySubQ/IM
TRT Adjunct (Standard)500-1000 IUTwice weeklySubQ/IM
HCG Monotherapy1500-2000 IU2-3x weeklyIM
Fertility (with FSH)1500-2000 IU2-3x weeklyIM
Cryptorchidism (Pediatric)1000-5000 IU2-3x weekly for 3-4 weeksIM
Ovulation Trigger (Female)5000-10,000 IUSingle doseIM/SubQ
PCT Protocol1000-1500 IUEvery other day for 2-3 weeksSubQ/IM

Reconstitution Instructions

Materials Needed:
  • HCG lyophilized powder vial (typically 5000 or 10,000 IU)
  • Bacteriostatic water or sodium chloride diluent (provided)
  • Insulin syringes (29-31 gauge for SubQ)
  • Alcohol prep pads
  1. 1 Remove vial and diluent from packaging
  2. 2 Clean rubber stoppers with alcohol swabs
  3. 3 Draw diluent into syringe (typically 1-2mL provided)
  4. 4 Slowly inject diluent into HCG vial, aiming at vial wall
  5. 5 Gently swirl to dissolve - do not shake vigorously
  6. 6 Allow to sit until completely dissolved and clear
  7. 7 Calculate concentration (e.g., 5000 IU in 2mL = 2500 IU/mL)
  8. 8 Label with reconstitution date and concentration
  9. 9 Store reconstituted HCG at 2-8°C
  10. 10 Use within 30-60 days

Interactions

++
Testosterone
Commonly combined in TRT to maintain testicular function and preserve fertility.
synergistic
~
Clomiphene (Clomid)
Use sequentially; both affect HPG axis.
monitor
+
Aromatase Inhibitors
Commonly combined; HCG increases intratesticular aromatase activity.
compatible
~
GnRH Analogs
Monitor combination effects on gonadotropin axis.
monitor
++
FSH (Follitropin)
Synergistic for fertility; 70-90% spermatogenesis induction rate.
synergistic
+
Kisspeptin
Complementary mechanisms for HPG axis stimulation.
compatible
~
Thyroid Hormones
HCG has weak TSH-like activity; monitor thyroid function.
monitor
+
Metformin
Protective combination for metabolic health.
compatible

What to Expect

Day 1-3
Cellular-level action begins; no immediate noticeable effects
Week 1-2
Testosterone increase detectable on labs; possible mood/energy improvement
Week 2-4
Testicular fullness/size improvement noticeable; improved 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

Side Effects & Safety

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

Stop Signs - Discontinue if:

  • Signs of gynecomastia (breast tenderness, swelling, nipple sensitivity)
  • Severe or persistent headaches
  • Signs of blood clots (leg swelling/pain, shortness of breath, chest pain)
  • Allergic reactions (rash, hives, difficulty breathing, facial swelling)
  • Severe abdominal pain or bloating in women (possible OHSS)
  • Testicular pain or swelling beyond normal
  • Significant mood changes (depression, aggression, severe irritability)
  • Vision changes

Contraindications

  • Hormone-sensitive cancers (prostate, breast)
  • Pregnancy (except as prescribed)
  • Precocious puberty risk in children

Quality Checklist

Good Signs

  • White to off-white lyophilized powder or cake in sealed vial
  • Completely clear solution after reconstitution
  • Proper labeling: Pregnyl, Novarel (urinary), Ovidrel (recombinant)
  • Clear expiration and lot number
  • Cold chain compliance (recombinant requires refrigeration throughout)

Warning Signs

  • Generic/compounding pharmacy products - quality varies
  • Ensure compounding pharmacy is accredited

Bad Signs

  • Cloudiness, discoloration, or floating particles indicates degradation
  • Compromised vial seal or expired product

References

  • Low-Dose Human Chorionic Gonadotropin Maintains Intratesticular Testosterone in Normal Men with Testosterone-Induced Gonadotropin Suppression
    Coviello AD, Matsumoto AM, Bremner WJ, et al.
    Journal of Clinical Endocrinology & Metabolism (2005)

    29 men randomized to testosterone enanthate plus 125, 250, or 500 IU HCG every other day. 250 IU maintained intratesticular testosterone within 7% of baseline, preserving fertility potential during TRT.

  • Human Chorionic Gonadotropin Monotherapy for the Treatment of Hypogonadal Symptoms in Men with Total Testosterone >300 ng/dL
    Alder NJ, Waguih WI, et al.
    International Journal of Impotence Research (2019)

    HCG monotherapy safe and efficacious for hypogonadal symptoms. Erectile dysfunction improved in 86% (19/22), libido in 80% (20/25). No thromboembolic events.

  • Fertility Induction in Hypogonadotropic Hypogonadal Men
    Rastrelli G, Corona G, Mannucci E, Maggi M
    Endocrine Reviews (2018)

    Combined HCG and FSH therapy induces spermatogenesis in 86% (95% CI 82-91%) of men with hypogonadotropic hypogonadism. HCG alone achieves 40% (95% CI 25-56%).

  • The Effectiveness of hCG and LHRH in Boys with Cryptorchidism: A Meta-Analysis of Randomized Controlled Trials
    Defined a, et al.
    Asian Journal of Andrology (2016)

    Meta-analysis of 13 studies with 872 boys and 1,174 undescended testes. Overall HCG success rate of 24%. Significant effect on bilateral but not unilateral cryptorchidism.

  • Efficacy and Safety of Human Chorionic Gonadotropin for Treatment of Cryptorchidism: A Meta-Analysis of Randomised Controlled Trials
    Defined a, et al.
    Journal of Pediatric Surgery (2018)

    Confirmed ~25% success rate for HCG in cryptorchidism treatment. All side effects were transitory and not severe.

Disclaimer

This information is for educational and research purposes only. Consult a healthcare professional before use.