HCG
Glycoprotein LH-analog hormone · FDA-approved for fertility (Pregnyl, Novarel, Ovidrel)
HCG (human chorionic gonadotropin) is the FDA-approved pregnancy hormone and the IVF (in vitro fertilization) trigger shot. It mimics luteinizing hormone (LH), which runs the gonads. Men on testosterone therapy run low doses to keep the testes making testosterone and sperm, backed by controlled trials.
At a glance
- Dose
- 250–500 IU on TRT; 1,000–2,000 IU post-cycle
- How often
- Every other day or 2–3 times a week on TRT
- How
- Under the skin; urinary trigger shots go into the muscle
- When
- Any time of day, just keep the schedule steady
- Cycle
- Continuous alongside testosterone, or 2–4 weeks post-cycle before clomiphene or enclomiphene
The 30-second versionEverything on this page, fast
TRT adjunct · Fertility · LH mimic · Testosterone
The LH signal you can inject. HCG acts directly on the gonad, so it keeps the testes producing testosterone through testosterone replacement therapy (TRT) and preserves the fertility and testicular size that testosterone alone shuts down, a use backed by controlled human trials. It is also the FDA-approved ovulation trigger shot in IVF.
The basics
- An FDA-approved glycoprotein hormone that acts like luteinizing hormone (LH), telling the gonads directly what to do.
- Injected and dosed in international units (IU) for the urinary forms (Pregnyl, Novarel); recombinant Ovidrel is dosed in µg.
Why people use it
- Preserves the testes on TRT. It acts straight on the Leydig cells to maintain the intratesticular testosterone that testosterone alone collapses, keeping fertility and testis size (Coviello 2005, Roth 2010).
- Drives the gonad when the pituitary is offline. It bypasses the pituitary and signals the testis or ovary directly, the basis for TRT-adjunct and post-cycle use.
- Triggers ovulation. It mimics the mid-cycle LH surge for final egg maturation and release, the FDA-approved basis of its IVF role.
- The bottom rung of a full-axis stack. It pairs with the upstream rungs (Gonadorelin, Kisspeptin-10) and with testosterone to cover the whole axis.
Stacks well with
- Gonadorelin works one rung up at the pituitary while HCG drives the gonad directly, for full-axis preservation.
- Kisspeptin-10 is the furthest-upstream gate at the hypothalamus, so the two cover the top and bottom rungs of the same ladder.
Good to know
- Raising testosterone means it can aromatize to estrogen. Bloating, nipple sensitivity or mood changes are the cue to reduce the dose or frequency.
- Injected HCG produces positive pregnancy tests and can interfere with HCG-based lab monitoring.
- Clinic doses differ by goal. The IVF trigger is a single 5,000–10,000 IU shot (or 250 µg Ovidrel) about 36 hours before egg retrieval. Male fertility induction runs 1,000–4,000 IU 2–3 times a week.
- Prohibited in male athletes at all times (WADA S2.2.1); not prohibited in females.
What it does
- Keeps the testes working on testosterone therapyIts top off-label use. Low doses preserve fertility and testis size on testosterone replacement therapy (TRT), backed by controlled trials.
- Drives the gonads with the pituitary offlineIt bypasses the pituitary and signals the testis or ovary directly, the basis for post-cycle and TRT add-on use.
- Triggers ovulationIt mimics the mid-cycle LH surge that matures and releases the egg, the FDA-approved basis of its IVF role.
- Supports male fertilityFDA-approved for male fertility in hypogonadotropic hypogonadism.
- Anchors a full-axis stackIt pairs with Gonadorelin at the pituitary, Kisspeptin-10 at the hypothalamus, and follicle-stimulating hormone (FSH) or testosterone.
How it works
Acts like LH, for days. HCG binds the LH/hCG receptor (LHCGR) on cells in the testes and ovaries. It does what the body's own LH does, but a heavy sugar coating slows its clearance, so one dose acts for days.
Keeps the testes making testosterone. In men it switches on the Leydig cells, which make testosterone inside the testes. That builds the high local level (10–100× the level in blood) sperm production needs. In controlled human trials it preserved sperm production and testis size while testosterone therapy shut down the body's own LH.
Triggers ovulation. In women it mimics the mid-cycle LH surge that matures and releases the egg, the basis of the IVF trigger shot.
How to dose it
Pregnyl and Novarel are dosed in international units (IU), Ovidrel in micrograms (µg).
Dose tiersFrom 250–500 IU on TRT to a 5,000–10,000 IU trigger shot.
- IVF trigger (women):
- One 5,000–10,000 IU urinary shot into the muscle, or 250 µg Ovidrel under the skin, ~36 hours before egg retrieval, once FSH matures the follicles.
- Male fertility:
- 1,000–4,000 IU into the muscle or under the skin, 2–3× per week, for months, adjusted to a mid-normal morning testosterone.
- On TRT:
- 250–500 IU under the skin every other day, or 2–3× per week. Controlled trials support doses as low as 125 IU every other day.
- Post-cycle:
- 1,000–2,000 IU into the muscle or under the skin, every other day for 2–3 weeks, then tapering.
How to injectUnder the skin for TRT and post-cycle doses, into the muscle for trigger shots.
- Under the skin:
- Abdomen (a couple of inches from the navel), outer thigh or love handles. Rotate sites. For TRT (250–500 IU) and post-cycle doses, and Ovidrel.
- Into the muscle:
- Upper outer buttock or outer thigh. Usual for urinary trigger shots and higher fertility doses.
- Mixing:
- Urinary HCG is a powder you mix first. Ovidrel comes prefilled.
Cycle and breaksContinuous on TRT, weeks post-cycle, months for fertility.
- On TRT:
- Continuous alongside testosterone. Recheck LH, FSH, estradiol and total testosterone periodically. Lower the dose if estradiol rises.
- Fertility induction:
- Often 3–6 months, adding FSH if sperm output stays incomplete after the first months.
- Post-cycle:
- 2–4 weeks of HCG, often followed by a SERM (selective estrogen receptor modulator) for 4–6 more weeks. Recheck testosterone, LH and FSH at the end.
- Estradiol watch:
- Bloating, nipple sensitivity or mood changes mid-cycle mean reassess dose and frequency.
Mixing the vialFor a 5,000 IU vial.
- Mix:
- 5,000 IU + 2 mL bacteriostatic water = 2,500 IU per mL, so on a U-100 syringe 250 IU is 10 units, 500 IU 20 units, 1,000 IU 40 units.
- Alternate dilution:
- 5,000 IU + 3 mL (a standard vial's maximum) = about 1,667 IU/mL. On U-100, 250 IU is 15 units, 500 IU 30 units, easier for TRT doses.
Best time to take it
Implied best time
Anytime (consistent, 2–3×/week)
Time of day barely matters. A steady schedule does, usually every other day or 2–3× per week on TRT.
- Its terminal half-life is roughly 24–36 hours, so one dose works across days and the exact hour carries little weight.
- Many users pair the HCG shot with their testosterone dose, simply as a routine anchor.
- The IVF trigger is the exception, a single dose timed ~36 hours before egg retrieval.
Sources:PMID 15713727DailyMed (Ovidrel)
What to stack it with
Partners work other rungs of the axis; skip a second LH analog.
HCG + TestosteroneThe classic TRT pairing.
- Why it works:
- Testosterone shuts down LH. HCG stands in, keeping testicular testosterone high (Coviello 2005, Roth 2010).
- The protocol:
- Weekly testosterone (100–200 mg cypionate or enanthate) plus HCG 250–500 IU every other day or 3× weekly. If estradiol rises, cut frequency first.
- Outcome:
- Testicular size and fertility held.
HCG + GonadorelinGonadorelin works the pituitary, HCG the gonad.
- Why it works:
- Gonadorelin (GnRH, gonadotropin-releasing hormone) makes the pituitary release LH and FSH. HCG drives the testes directly.
- The protocol:
- Gonadorelin 100 mcg 2–3× per week plus HCG 250–500 IU every other day or 3× weekly, both under the skin.
- Outcome:
- Keeps pituitary and testes working on TRT. Also fertility prep before stopping testosterone.
HCG + Kisspeptin-10Kisspeptin-10 primes the axis top, HCG the bottom.
- Why it works:
- Kisspeptin-10 triggers the GnRH pulse. HCG drives the testes directly.
- The protocol:
- Kisspeptin-10 6.4 nmol/kg under the skin, pulsed, plus HCG 250–500 IU on alternating days.
- Outcome:
- Whole-axis stimulation for fertility research.
HCG + SERMThe post-cycle restart pairing.
- Why it works:
- HCG wakes the Leydig cells. The SERM then blocks estrogen feedback, so LH and FSH rise.
- The protocol:
- HCG 1,000–2,000 IU under the skin or into the muscle every other day for 2–3 weeks, then clomiphene 25–50 mg/day or enclomiphene 12.5–25 mg/day for 4–6 weeks.
- Outcome:
- Your own testosterone restarts. Some clinicians prefer Gonadorelin for its natural LH pulses.
Support nutrients
These give the testes what they need to answer HCG's signal.
Keep the testosterone signal switched onUnderfed, overtrained or short on sleep, the body deprioritizes testosterone.
- Adequate calories:
- Eat at or above maintenance. A severe deficit blunts the pathway HCG activates.
- Cortisol management:
- Chronic stress and overtraining raise cortisol, which suppresses LH and testosterone-making.
- Sleep (7–9 h):
- The largest testosterone pulse comes during sleep.
Testosterone building blocksTestosterone is built from cholesterol, with these nutrients.
- Cholesterol (dietary fat):
- The precursor of every steroid hormone. Very-low-fat diets can blunt testosterone.
- Zinc 15–30 mg/day:
- Picolinate or bisglycinate, with food. Deficiency suppresses testosterone output. At 30 mg long-term, add 1–2 mg copper bisglycinate.
- Vitamin D 2,000–5,000 IU/day:
- Leydig cells carry vitamin D receptors. Dose to blood level (50–80 ng/mL is a common clinical target), with a fatty meal.
- Magnesium 300–400 mg/day:
- Glycinate or malate at night. Low magnesium tracks with lower testosterone. Avoid oxide, which absorbs poorly.
- Boron 3–6 mg/day:
- Calcium fructoborate or sodium borate with food. Supports free testosterone by lowering SHBG (sex hormone-binding globulin).
Protect the Leydig cellsMaking testosterone creates oxidative stress, and the testes are sensitive to it.
- Vitamin C 500–1,000 mg/day:
- Ascorbic acid, split across the day. Mops up the oxidative stress that making testosterone creates.
- Vitamin E 100–200 IU/day:
- Mixed tocopherols with a fatty meal. Protects Leydig cells in oxidative-stress models.
- Selenium 100–200 mcg/day:
- Selenomethionine, never above 400 mcg/day. Supports sperm production.
Side effects and what to watch
What people notice. Injection-site pain, redness or bruising, headache, fatigue and irritability, mostly mild. In men, the extra testosterone can convert to estrogen, bringing breast tissue growth (gynecomastia), fluid retention, acne, mood changes or testicular discomfort.
How people handle it. These effects scale with dose, so low doses are preferred for keeping the testes working.
Skip it or take care if. The label's main serious risk in women is ovarian hyperstimulation syndrome (OHSS) after FSH stimulation, with enlarged ovaries, fluid shifts and, in severe cases, blood clots. Ovulation induction also raises the chance of multiples.
Worth knowing. Injected HCG turns pregnancy tests positive. The "HCG diet" harms (gallstones, electrolyte imbalance, heart-rhythm problems) come from its 500-calorie-a-day regimen, not the hormone.
Common questions
How is HCG dosed?
On TRT, 250–500 IU under the skin every other day or 2–3× per week. Male fertility runs 1,000–4,000 IU 2–3× per week. The IVF trigger is one 5,000–10,000 IU shot (or 250 µg Ovidrel).
Why do men on TRT add HCG?
Testosterone therapy shuts off LH, so the testes shrink and stop making sperm. Low-dose HCG keeps them working, preserving fertility and testis size in controlled trials.
Do I need to cycle HCG?
On TRT it runs continuously. Fertility induction runs 3–6 months. After a steroid cycle it runs 2–4 weeks, often before clomiphene or enclomiphene.
HCG vs gonadorelin, what's the difference?
Gonadorelin acts upstream, making the pituitary release its own LH and FSH. HCG acts on the gonads directly and lasts much longer, so it works even with the pituitary suppressed.
What's the difference between Pregnyl/Novarel and Ovidrel?
Pregnyl and Novarel come from urine, are dosed in IU and usually go into the muscle. Ovidrel is recombinant, dosed in µg, under the skin. 250 µg ≈ 5,000–10,000 IU, so the doses don't swap one for one.
Does HCG help with weight loss?
No. A randomized placebo-controlled trial and a meta-analysis of 24 trials found no benefit beyond calorie restriction, which drives the 500-calorie HCG diet. US regulators pulled over-the-counter homeopathic HCG weight-loss products in 2011.
Deep dive
Doses used in studies · Molecular identity · References
09From the researchDoses used in studies
These are the doses used in the human trials, from low-dose TRT studies in men to the IVF trigger and the weight-loss trials.
| Dose | Route | Model | Outcome | Sources: |
|---|---|---|---|---|
| 125 / 250 / 500 IU every other day ×3 wk (+ 200 mg testosterone/wk) | SC/IM | Human RCT, healthy men, n=29, suppressed gonadotropins | Intratesticular testosterone preserved dose-dependently; testosterone-alone dropped it ~94%; low-dose HCG kept it in normal range | PMID 15713727 |
| 15 / 60 / 125 IU every other day | SC | Human, men with experimental gonadotropin deficiency | Intratesticular testosterone rose dose-dependently even at very low doses, which establishes the micro-dose principle | PMID 20484472 |
| 5,000 kJ/day diet + HCG vs placebo (6 wk) | IM | Human RCT, 40 obese women, double-blind | No advantage over placebo on any measured variable; "no rationale for the use of HCG injections in obesity" | PMID 2405506 |
| Simeons protocol (HCG diet), 24 trials pooled | IM | Human meta-analysis (criteria-based) | No evidence HCG is effective for obesity (no weight loss, fat redistribution, hunger reduction, or well-being benefit) | PMID 8527285 |
| 250 µg recombinant vs 5,000 IU urinary IM | SC | Human, infertile women in ART | Single trigger dose induces final follicular maturation/ovulation; recombinant SC non-inferior to urinary IM | DailyMed (Ovidrel) |
10ChemistryMolecular identity
- CAS number
- 9002-61-3 (chorionic gonadotrophin)
- Structure / class
- Glycoprotein hormone (gonadotropin family), NOT a simple peptide; no single small-molecule formula or sequenceUniProt P01215 / P0DN87
- Subunits
- Heterodimer: shared α-subunit CGA (92 aa, UniProt P01215) + hCG-specific β-subunit CGB (145 aa, UniProt P0DN87), heavily glycosylatedUniProt P01215 / P0DN87
- Molecular weight
- ~36.7 kDa (intact glycosylated heterodimer)UniProt P01215 / P0DN87
- Molecular target
- LH/CG receptor (LHCGR) agonist, LH analog on gonadal Leydig/granulosa cellsOvidrel FDA label
- Forms
- Urinary (Pregnyl/Novarel; dosed IU, IM) · recombinant choriogonadotropin alfa (Ovidrel; dosed µg, SC; 250 µg ≈ 5,000–10,000 IU)Ovidrel FDA label
- Half-life
- ~24–36 h terminal (recombinant SC median 29.2 h)PMID 33982429; Ovidrel label (PK)Half-life curve →
- Brand / approval
- FDA-approved: Pregnyl, Novarel (urinary), Ovidrel (recombinant); fertility / ovulation trigger / male hypogonadismOvidrel FDA label
- Anti-doping status
- Prohibited in males at all times (WADA S2.2.1, chorionic gonadotrophin); not prohibited in femalesWADA 2026
11Primary sourcesReferences
- UniProt P01215UniProt P01215. Glycoprotein hormones alpha chain (CGA), shared α-subunit (92 aa)
- UniProt P0DN87UniProt P0DN87. Choriogonadotropin subunit beta (CGB), 145 aa mature (legacy P01233 demerged)
- PMID 15713727Coviello et al., J Clin Endocrinol Metab 2005 (low-dose hCG maintains intratesticular testosterone)
- PMID 20484472Roth et al., J Clin Endocrinol Metab 2010 (dose-dependent ITT with very low-dose hCG)
- PMID 2405506Bosch et al., S Afr Med J 1990 (HCG & weight loss, double-blind placebo-controlled RCT)
- PMID 8527285Lijesen et al., Br J Clin Pharmacol 1995 (Simeons HCG therapy, criteria-based meta-analysis)
- PMID 33982429Kyhl et al., Clin Transl Sci 2021 (first-in-human PK/PD of recombinant hCG)
- DailyMed (Ovidrel)OVIDREL (choriogonadotropin alfa) FDA Prescribing Information
- FDA Consumer Update 2011FDA/FTC action removing OTC homeopathic HCG weight-loss products (2011)
- WADA 2026WADA 2026 Prohibited List, S2.2.1. Chorionic gonadotrophin prohibited in males
Reviewed by Ki Researcher Team · Research use only · Not medical advice · Updated 2026-09-24