HCG
Human Chorionic Gonadotropin
Human chorionic gonadotropin (hCG) is an injectable placental glycoprotein hormone that mimics luteinizing hormone (LH), directly stimulating testicular Leydig cells to produce testosterone. In men it is used clinically to treat hypogonadotropic hypogonadism, to induce or restore sperm production, and — in the anabolic-steroid context — to counter testicular shutdown and shrinkage or preserve fertility during/after testosterone use. It is not an anabolic steroid and is not liver-toxic, but it is not benign: because it drives testosterone and estradiol, the main risks include gynecomastia, acne, fluid retention, mood changes, possible rise in red-cell mass (secondary erythrocytosis), and — with prolonged or high dosing — desensitization of the testes. It does not restore your own brain-pituitary signaling; endogenous LH/FSH stay suppressed while it is used. Human evidence is strongest for surrogate endpoints (intratesticular testosterone, sperm induction) and is limited/small for safety in recreational users. This is a hormone that belongs under endocrinologist supervision with bloodwork, not self-management.
Mechanism of action
Pharmacokinetics
Biphasic elimination; terminal serum elimination half-life approximately 32-33 hours after intramuscular or subcutaneous injection (immunoreactive hCG). An earlier study reported a longer apparent serum half-life after subcutaneous versus intramuscular dosing due to slower absorption.
Serum hCG peaks roughly 20 hours post-injection and remains detectable for several days; less than ~10% of peak activity remains by day 8. Testosterone/steroidogenic response persists over multiple days, which is why intermittent (e.g., every-other-day or 2-3x weekly) dosing schedules are used clinically.
Injectable only (subcutaneous or intramuscular); it is a glycoprotein and is not orally bioavailable. Subcutaneous and intramuscular routes are bioequivalent in extent of absorption.
Cleared by renal excretion and hepatic/tissue metabolism of the glycoprotein; intact hCG and beta-subunit fragments are excreted in urine (the basis of pregnancy tests). Note for monitoring/washout context only, not for evading testing: detectable in serum/urine for roughly 8-10+ days after a dose.
For monitoring and washout planning, not drug-test evasion.
Physiological & performance effects
- Raises serum and intratesticular testosterone by directly stimulating Leydig cells
- Maintains or restores testicular size/function during or after exogenous androgen use
- Can reverse or prevent testosterone-therapy-induced suppression of spermatogenesis and, in hypogonadotropic hypogonadism, induce sperm production (often combined with FSH)
- Increases estradiol secondary to aromatization of the testosterone it generates
- Preserves fertility potential in hypogonadal men of reproductive age when used instead of or alongside carefully managed testosterone
Adverse effects by system
No adequate hCG-specific human cardiovascular outcome data. Plausible indirect effects via elevated testosterone and estradiol (fluid/sodium retention, edema, and possible increases in red-cell mass/hematocrit that could raise thrombotic risk). Gonadotropin therapy generally is well tolerated, but cardiovascular risk in recreational/androgen-user populations is uncharacterized.
Not hepatotoxic. hCG is a peptide/glycoprotein hormone, not a 17-alpha-alkylated oral steroid; there is no evidence of intrinsic liver injury. No clinically significant hepatic adverse signal reported.
Raises testosterone and estradiol while further suppressing endogenous LH and FSH via negative feedback; it does not restore hypothalamic-pituitary function. Prolonged or high-dose use can desensitize/downregulate Leydig-cell LH-receptor responsiveness. Estradiol elevation can drive gynecomastia.
In the therapeutic setting these are the intended actions (increased testicular testosterone, restored/maintained spermatogenesis and testicular volume). Adverse reproductive effects relate to estrogen excess (gynecomastia, breast tenderness) and, with prolonged high-dose use, potential Leydig-cell desensitization.
No adequate hCG-specific controlled data. Mood lability, irritability, or libido changes are reported anecdotally in the setting of shifting testosterone/estradiol; magnitude and causality are not established for hCG specifically.
No known clinically significant direct nephrotoxicity and no adequate hCG-specific human renal-outcome data. Fluid retention is possible secondary to hormonal effects.
No adequate direct hCG-specific human data. Because it raises testosterone, secondary erythrocytosis (rising hematocrit/hemoglobin) is biologically plausible and warrants CBC monitoring, as with any therapy that elevates androgens.
Acne and oily skin can occur secondary to increased androgen production. Local injection-site reactions (pain, redness, swelling, bruising) are reported; contemporary cohorts report mild side effects in a minority of treated men.
HPTA suppression & recovery
Suppression: hCG does not restore your own hypothalamic-pituitary output; while it is administered, endogenous LH and FSH remain suppressed by testosterone/estradiol feedback, and prolonged high-dose use can desensitize the Leydig cells it acts on. It stimulates the testis directly rather than rebooting the axis.
Any HPTA recovery or fertility plan after androgen use should be individualized and directed by an endocrinologist or reproductive urologist with serial bloodwork (LH, FSH, total/free testosterone, estradiol) and, where fertility is the goal, semen analysis. If a selective estrogen receptor modulator is considered as part of recovery, only a single-SERM, physician-supervised approach is appropriate; this monograph does not describe or endorse multi-SERM regimens or any self-directed protocol. Timelines vary widely and cannot be promised.
Monitoring
Cadence: Baseline before starting, an early recheck at roughly 4-8 weeks to assess testosterone/estradiol/hematocrit response, then periodic monitoring every few months while on therapy and after changes; fertility endpoints (semen analysis) reassessed over months given the multi-month timeline to spermatogenesis.
- New or worsening breast tissue growth or tenderness (gynecomastia)
- Signs of blood clot: calf swelling/pain, chest pain, shortness of breath, sudden severe headache or visual change
- Rising hematocrit or symptoms of thickened blood (headache, flushing, dizziness)
- Marked mood changes or aggression
- Injection-site infection (spreading redness, warmth, pus, fever)
- Persistent edema or rapid weight gain from fluid retention
Contraindications
- Known hypersensitivity to hCG or excipients
- Known or suspected androgen-dependent malignancy (e.g., prostate cancer, male breast cancer)
- Precocious puberty
- Active or prior hormone-related thromboembolic disease (use only under specialist risk assessment)
- Any use outside qualified medical supervision, particularly for fertility or hypogonadism management
- Pregnancy-related or assisted-reproduction indications in women are outside the scope of this male-focused monograph
Interaction profile
- ModerateWith another gonadotropin (hCG / hMG): Hormonal
- ContraindicatedWith DNP: Additive cardiovascular strain
Check a specific combination in the interaction checker.
Reducing harm & when to stop
- Treat hCG as a prescription hormone requiring an endocrinologist or reproductive urologist and baseline plus follow-up bloodwork — not a self-managed add-on.
- Because hCG raises estradiol as well as testosterone, watch for breast tenderness/gynecomastia and report it early rather than self-treating with additional agents.
- Get a CBC/hematocrit checked — rising red-cell mass from androgen elevation can increase clot risk; stop and seek care for leg swelling, chest pain, or breathlessness.
- Prolonged or high-dose use can desensitize the testes; dose ranges in the literature are tied to specific medical goals and monitoring, not to maximizing output.
- Do not use to 'boost' performance or physique; the documented benefits are for hypogonadism and fertility under supervision.
- Stop and seek medical care for signs of clot, severe headache or visual change, spreading injection-site infection or fever, or marked mood changes.
- Fertility restoration takes months and outcomes vary — decisions about hCG, FSH, or a single SERM should be made with a specialist, and multi-SERM or self-directed 'recovery stacks' are not supported here.
- Never share needles; use sterile injection technique to avoid local and systemic infection.
Citations (8)
Every clinical claim above is tied to a primary source. Overall evidence grade B — graded to the best available evidence for its core claims.
- 01
Low-dose hCG (125-500 IU every other day) maintains intratesticular testosterone in the normal range in a dose-dependent manner in men with testosterone-induced gonadotropin suppression, while LH and FSH remain profoundly suppressed.
- 02
hCG serum elimination half-life is approximately 32-33 hours; serum hCG peaks about 20 hours after injection and falls below ~10% of peak by day 8; subcutaneous and intramuscular 10,000 IU are bioequivalent in extent of absorption.
- 03
After subcutaneous injection of 5,000 IU hCG the peak concentration is delayed and serum half-life prolonged versus intramuscular, but testosterone, LH and FSH responses are equivalent; subcutaneous dosing is as effective as intramuscular for steroidogenesis.
- 04
In men with hypogonadotropic hypogonadism and azoospermia, gonadotropin therapy induced spermatogenesis in 74% (78% with combined hCG+FSH vs 33% with hCG monotherapy), achieved pregnancy in 68%, with a median 7 months to first sperm and mild side effects in 16% — indicating efficacy and general tolerability.
- 05
In congenital hypogonadotropic hypogonadism, a low-dose hCG regimen (500 IU three times weekly) with FSH and testosterone induced spermatogenesis comparably to conventional high-dose hCG (2000 IU three times weekly), with 76.7% achieving spermatogenesis at a median of ~12 months.
- 06
hCG therapy can reverse testosterone-therapy-induced azoospermia and maintain elevated intratesticular testosterone, supporting its use for fertility preservation in hypogonadal men.
- 07
Exogenous testosterone suppresses intratesticular testosterone and spermatogenesis; hCG (including low-dose hCG alongside testosterone) is a strategy to protect testicular function, and routine aromatase-inhibitor use is not recommended due to lack of long-term data.
- 08
In anabolic-androgenic steroid-induced hypogonadism, management may include hCG (with or without testosterone) and single selective estrogen receptor modulators; complications such as gynecomastia and testicular atrophy are recognized in this context.
ReviewAnabolic steroid-induced hypogonadism: diagnosis and treatment.DOI 10.1016/j.fertnstert.2014.02.002 ↗
Last reviewed 2026-07-06 · Verified against PubMed · Educational, not medical advice