HCG
HCG (human chorionic gonadotropin) is a placental glycoprotein hormone acting as a luteinizing-hormone analog, studied for supporting endogenous testosterone production, testicular volume, and fertility; research protocols typically use 250 IU every other day subcutaneously.
Best for
Researched for supporting endogenous testosterone production, testicular volume, and fertility in men with hypogonadotropic hypogonadism, and studied as an adjunct to preserve gonadal function during or after exogenous androgen exposure.
What to expect
Research reports a rise in serum testosterone within hours to days of administration, while measurable increases in testicular volume and spermatogenesis are generally observed over weeks to months of continued dosing.
Pairs with
In fertility-focused research it is frequently combined with FSH preparations (such as human menopausal gonadotropin or recombinant/corifollitropin alfa) to support spermatogenesis, and it is studied alongside testosterone-replacement or post-cycle regimens.
In published research it is reconstituted from lyophilized powder and given by injection (FDA labeling specifies intramuscular; subcutaneous dosing is common off-label), typically two to three times weekly, with dose individualized to the studied indication.
- How often
- Every other day
- When
- Morning
- Route
- Subcutaneous
- Vial & water
- 5,000 IU vial in 2 mL = 2,500 IU/mL · 250 IU = 10 units on a U-100 syringe
- Cycle
- Often used continuously with TRT
The same numbers the goodtides app and the Dose Calc use — a research reference, not a prescription. Responses are individual; research protocols start at the low end.
Human chorionic gonadotropin (HCG) is a heterodimeric glycoprotein hormone produced naturally by placental trophoblast tissue, composed of a 92-amino-acid alpha subunit (shared with LH, FSH and TSH) and a unique 145-amino-acid beta subunit, heavily glycosylated and totaling roughly 237 residues.
Unlike most research peptides, chorionic gonadotropin is FDA-approved as a prescription drug (e.g., Pregnyl, Novarel) for prepubertal cryptorchidism, female ovulation induction, and male hypogonadotropic hypogonadism; its use on or after exogenous androgen therapy is not an FDA-approved indication.
It acts as a luteinizing-hormone analog, binding the LH/CG receptor (LHCGR) — a Gs-coupled G-protein-coupled receptor expressed on testicular Leydig cells — with affinity reported several-fold higher than LH itself. Receptor activation raises intracellular cAMP and drives protein-kinase-A-mediated steroidogenesis, stimulating endogenous testosterone production and supporting testicular function.
Research has characterized its role in pubertal induction, spermatogenesis support, and maintenance of testicular volume in hypogonadotropic states.
- Half-life
- Biphasic; ~5-9 hr initial, terminal ~23-33 hr
- Peak
- ~6-12 hr post-IM (serum hCG)
- Absorption
- Slower, more sustained after IM than IV
- Bioavailability
- Injectable (IM per label; SC off-label); not orally bioavailable
References3
- DailyMed - PREGNYL (chorionic gonadotropin for injection) FDA label
- Agarwal S et al. - Testosterone versus hCG in hypogonadotropic hypogonadism: comparing clinical effects and evaluating current practice (Glob Pediatr Health)
- Choi J, Smitz J - Luteinizing hormone and human chorionic gonadotropin: origins of difference (Mol Cell Endocrinol)
Log every dose, count every vial, and verify your batches — free in the goodtides app.
This page is educational reference material about compounds studied in research settings. It is not medical advice, and nothing here is a recommendation to buy, possess, or use any compound. Research findings described are from published literature; individual compounds may not be approved for human use. Talk to a licensed clinician about anything that affects your health.