HCG
Human Chorionic Gonadotropin
A gonadotropin that stimulates the body's own testosterone — used in TRT support and fertility.
Class
Human chorionic gonadotropin (LH analogue)
Half-life
~24–36 hours
Evidence
Randomized human trials
Randomized human trials
Supported by randomized controlled trials in humans. Several compounds at this level are FDA-approved for specific indications.
Overview
HCG mimics luteinizing hormone (LH), signalling the testes to produce testosterone and, importantly, to keep functioning. It is FDA-approved for specific uses (hypogonadotropic hypogonadism, certain fertility contexts, undescended testes), and it has a well-established clinical track record.
In the testosterone-therapy world it is used to prevent the testicular shutdown and fertility loss that exogenous testosterone causes, and sometimes to restart natural production after a cycle. In women it triggers ovulation in fertility protocols. It is a hormone with real effects and real contraindications, especially around hormone-sensitive cancers.
How it works
- Agonises the LH receptor on testicular Leydig cells, stimulating endogenous testosterone production.
- Maintains testicular size and spermatogenesis during exogenous testosterone therapy.
- In women, triggers ovulation as part of fertility protocols.
What the research shows
Researched effects
- Maintained intratesticular testosterone and fertility during TRT (human trials)
- Restored testosterone production in hypogonadotropic hypogonadism
- Triggers ovulation in assisted reproduction
Limitations & what it won't do
- Not a fat-loss drug — the 'HCG diet' is discredited and potentially unsafe.
- Can aromatise to estrogen, causing gynecomastia if unmanaged.
- Contraindicated in hormone-sensitive cancers.
Dosing protocols
These ranges reflect published trials and community protocols. They are reference information, not a prescription. Doses are per injection unless noted.
TRT support (reference)
250–500 IUUsed to preserve fertility/testicular function on TRT. Doses and use should be directed by a prescriber.
Reconstitution & measuring your dose
Handling
- Typical vial sizes
- 5 mg
- Suggested BAC water
- 3 mL
- Storage
- Refrigerate reconstituted HCG at 2–8 °C.
- After reconstitution
- Reconstituted: approximately 30–60 days refrigerated.
Why 3 mL? HCG is dosed in international units. A 5000 IU vial reconstituted in 3 mL gives ~1667 IU/mL, so 250 IU is ~15 units and 500 IU ~30 units on a U-100 syringe.
Dose calculator
Draw to
15units
= 0.15 mL · 16.67 mcg per unit
Concentration
1666.7 mcg/mL
Doses per vial
20
Side effects
Common
- Injection-site reactions
- Acne and oily skin (from raised testosterone)
- Water retention
- Mood changes
Serious / rare
- Gynecomastia from estrogen conversion
- Ovarian hyperstimulation (in women)
- Worsening of hormone-sensitive cancers
- Blood clots (rare)
Contraindications & interactions
Do not use if you have
- Active cancer or current oncology treatment
Contraindicated in hormone-sensitive cancers (prostate, breast) and any active malignancy influenced by sex hormones.
- Pregnant, breastfeeding, or trying to conceive
Not for use in pregnancy outside supervised fertility care.
Use caution if you have
- Past cancer diagnosis (in remission)
Hormone-sensitive cancer history requires oncology clearance.
- Cardiovascular disease
Raised testosterone and fluid retention can affect cardiovascular status.
Medication interactions
- monitorTestosterone or anabolic therapy — Commonly used together to preserve fertility; a prescriber should coordinate dosing and estrogen management.
What to monitor
- Testosterone and estradiol levels
- Hematocrit
- Prostate health in older men
Commonly combined with
References
- Coviello AD et al. — Low-dose hCG maintains intratesticular testosterone in normal menJ Clin Endocrinol Metab 2005;90:2595-2602
Research & educational information only — not medical advice.
You must be 18 or older to use this site. The peptides described are presented as research chemicals intended for research purposes only. Most are not approved by the FDA for human use. Dosing ranges reflect what has appeared in the scientific literature or community protocols and are not prescriptions. Nothing here replaces evaluation by a licensed physician who knows your full medical history.
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