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HCG

FDA Approved

Human Chorionic Gonadotropin

Human Chorionic Gonadotropin, an FDA-approved gonadotropin used clinically for hypogonadotropic hypogonadism, cryptorchidism, and ovulation induction. Widely researched for maintaining testicular function.

Subcutaneous injectionIntramuscular injectionHormonalReproductive

Dose

500-1000 IU

Route

Subcutaneous injection, Intramuscular injection

Cycle

Variable, often 3-10 weeks when used alongside testosterone, or specific protocols for fertility research (e.g., 5-10 days for ovulation induction)

Storage

Refrigerate at 2-8°C (36-46°F), protected from light.

What is HCG?

Human Chorionic Gonadotropin (hCG) is a glycoprotein hormone endogenously produced by the placenta during pregnancy. Structurally similar to Luteinizing Hormone (LH), it binds to and activates the LH/choriogonadotropin receptor (LHCG-R) in the gonads. In male research subjects, this activation stimulates Leydig cells to produce testosterone and supports spermatogenesis, maintaining testicular function. In female research subjects, it mimics the LH surge, triggering ovulation and supporting corpus luteum function. hCG is an FDA-approved drug with specific indications for female infertility (ovulation induction), hypogonadotropic hypogonadism in males, and cryptorchidism in prepubertal males. Its widespread use in research protocols often explores its utility in preventing testicular atrophy and maintaining endogenous testosterone production during exogenous androgen administration.

Key Benefits

  • Supports endogenous testosterone production
  • Maintains testicular volume
  • Ovulation induction (clinical)

🐾 Griffin Says...

HCG is an FDA-approved gonadotropin with decades of controlled human use in fertility and hypogonadism, so the evidence base here is real, not internet folklore. The catch is that it is a hormone: dose, frequency and bloodwork matter, and it is easy to overshoot estradiol. Best suited to people already working with a clinician on testicular function or fertility, not to someone chasing a general wellness bump.

Molecular Information

Molecular weight

36,700 Da (alpha subunit 14,500 Da, beta subunit 22,200 Da)

Length

237 amino acids (alpha subunit 92, beta subunit 145)

Type

Glycoprotein hormone

Amino acid sequence

Alpha subunit: APDVQDCPECDPFFSQPGAPILQCMGCCFSRAYPTPLRSKKTMLVQKNVTSESTCCVAKSYNRVTVMGGFKVENHTACHCSTCYYSKH Beta subunit: SKEPLRPRCRPINATLAVEKEGONLVTVQVNTSYAVIRLPGCPKGDHPPYSLRPCDIMISRLPGCAAHADPLTPCDGPPDTPSFPQSLP

hCG is a glycoprotein composed of two noncovalently linked subunits: an alpha subunit (identical to LH, FSH, and TSH) and a beta subunit (which confers its specific biological activity and is homologous to the LH beta subunit, but with a C-terminal extension).

Pharmacokinetics

Time to peak

Approximately 6 hours for intramuscular injection, 16 hours for subcutaneous injection.

Half-life

24 h

Time to clear

Elimination takes several days due to its half-life.

DoseEstimated plasma concentration144 h

Stenman, U. H., et al. (1993). Human chorionic gonadotropin. Clinical Chemistry, 39(8), 1605-1613. [Note: PK values can vary based on dosage and administration route.]

Research Indications

  • Treatment of hypogonadotropic hypogonadism

    FDA-approved indication. In males, hCG stimulates the Leydig cells to produce testosterone and supports spermatogenesis, maintaining fertility and secondary sexual characteristics. Evidence: FDA-approved labeling, multiple human clinical trials.

  • Prevention of testicular atrophy during exogenous androgen administration

    Widely studied and frequently used in research protocols. hCG maintains testicular volume and function by providing exogenous LH-like signaling, thereby preventing suppression of endogenous testosterone production and spermatogenesis. Evidence: Numerous smaller human studies and animal models, off-label use.

  • Cryptorchidism (undescended testes)

    FDA-approved indication for prepubertal males. hCG can induce testicular descent by stimulating testosterone production. Evidence: FDA-approved labeling, human clinical trials.

Research Protocols

GoalDoseFrequencyRoute
Testosterone Production in Male Hypogonadism500-1000 IU2-3 times per weekSubcutaneous or Intramuscular
Maintenance of Testicular Function (during exogenous androgen use)250-500 IU2-3 times per weekSubcutaneous or Intramuscular
Ovulation Induction (in pre-ovulatory women, following FSH/LH stimulation)5,000-10,000 IU (single dose)OnceSubcutaneous or Intramuscular
Cryptorchidism (Prepubertal Males)500-1000 IU3 times per week for 3 weeksIntramuscular
Spermatogenesis Induction (secondary to other treatments)1,000-2,000 IU2-3 times per weekIntramuscular

Precise timing relative to meals or other compounds is generally not critical, but consistency is recommended for daily or every-other-day protocols.

Peptide Interactions

  • Follicle-Stimulating Hormone (FSH) / Menotropins (hMG)

    In female fertility research, hCG is often administered after FSH or menotropin treatment to trigger final follicular maturation and ovulation, mimicking the natural LH surge. This combination is a standard protocol.

    Synergistic

  • Testosterone/Anabolic Androgenic Steroids

    Used concurrently in male research subjects to mitigate suppression of endogenous testosterone production and testicular atrophy caused by exogenous androgens. hCG stimulates Leydig cells directly, maintaining testicular size and function.

    Compatible

  • Gonadotropin-Releasing Hormone (GnRH) Agonists/Antagonists

    These compounds affect endogenous gonadotropin release. hCG's direct action on the LHCG-R might bypass some GnRH effects, but complex interactions can occur in fertility protocols. Careful monitoring of hormone levels is essential.

    Monitor Combination

  • Aromatase Inhibitors (AIs)

    hCG stimulates testosterone production, which can lead to increased estrogen conversion. AIs may be used to manage elevated estradiol levels, but this introduces additional variables that require careful consideration and monitoring in research.

    Monitor Combination

  • Insulin

    Some research suggests hCG may have mild effects on glucose metabolism. For research subjects with diabetes or those using insulin, blood glucose levels should be monitored closely.

    Use Caution

How to Reconstitute

  1. 1Ensure both the hCG vial and bacteriostatic water vial are at room temperature.
  2. 2Remove the protective caps from both vials and wipe the rubber stoppers with alcohol swabs, allowing them to air dry.
  3. 3Using a sterile syringe, draw the desired amount of bacteriostatic water (e.g., 1mL per 5,000 IU vial for a concentration of 5,000 IU/mL).
  4. 4Slowly inject the bacteriostatic water into the hCG vial, aiming the needle at the glass wall rather than directly onto the powder.
  5. 5Gently swirl the vial (do not shake) until the lyophilized powder is completely dissolved. This may take a few minutes.
  6. 6Once dissolved, the solution should be clear and free of particulate matter. Store reconstituted solution as directed.

Reconstitution with bacteriostatic water is preferred due to its benzyl alcohol content, which acts as an antimicrobial agent and extends shelf life. Avoid shaking forcefully; gently swirl to dissolve.

What to Expect

  • Increased endogenous testosterone production (male research subjects).
  • Maintenance of testicular volume or prevention of atrophy (male research subjects).
  • Stimulation of ovulation (female research subjects, as part of specific fertility research protocols).
  • Potential for injection site reactions (e.g., redness, pain, swelling).
  • Transient breast tenderness or mild fluid retention in some research subjects due to hormonal fluctuations.
  • Mood changes due to altered hormone levels.

Side Effects & Safety

  • Always use sterile techniques for reconstitution and administration to prevent infection.
  • Carefully monitor research subjects for signs of ovarian hyperstimulation syndrome (OHSS) in female fertility research, particularly with higher doses.
  • Observe for potential allergic reactions (e.g., rash, itching, swelling, difficulty breathing) and discontinue use if suspected.
  • Regular monitoring of hormone levels (e.g., testosterone, estradiol) is advisable during research protocols.
  • Research subjects with a history of hormone-sensitive cancers or blood clots should be excluded or carefully monitored.
  • Not for use in research subjects with primary testicular failure, as hCG requires functional Leydig cells.

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Peptides discussed here are for research purposes only. Nothing on this page is medical advice. Always consult a qualified professional before making health decisions.