Peptides

HCG

Also called Human Chorionic Gonadotropin · Pregnyl · Ovidrel · Ovitrelle · Choragon

hCG is used to support testosterone and sperm production in some men with low hormone signals, and to trigger ovulation in fertility treatment. People on TRT also seek it to maintain testicular size or preserve fertility. Those goals need different treatment plans.

Open the plotter Sources

Dosage & duration

Separate adult treatment examples in IU. Each row has its own population and source; they do not form one hCG regimen.

Male fertility: deficient hormone signals

Published example · product-specific

Dose: 500–2,500 IU per injection
How often: 2–3 times weekly initially
How long: Response-guided; no fixed course specified

AUA/ASRM guidance for idiopathic hypogonadotropic hypogonadism. FSH may be added after testosterone normalizes. Product and injection route must match the prescription.

Sources: 2

Alongside TRT: Hsieh study

Published example · product-specific

Dose: 500 IU per injection
How often: Every other day, into muscle
How long: Ongoing use; follow-up averaged 6.2 months

A 26-man retrospective study, not a standard cycle. This off-label add-on does not guarantee fertility; the guideline considers supporting evidence too limited to recommend it for that purpose.

Sources: 4 · 2

IVF trigger: Zivafert PFS, UK label

Product label

Dose: 5,000 or 10,000 IU
How often: One injection, 24–48 hours after the last FSH/hMG dose
How long: One trigger in a monitored fertility cycle

For women undergoing ART after adequate follicle growth. The label permits injection under the skin or into muscle; the clinic sets the exact timing.

Sources: 3

IU describes hCG activity, not syringe volume. The plot’s starting amount is a simulation example, not a dose recommendation. Ovidrel uses different labeled units.

More quick facts

Male hormone support: Signals the testes to make testosterone; Sources : 1
Fertility treatment: Different roles in men and women; Sources : 2 · 3
Main trade-offs: Extra injections and hormone effects; Sources : 1 · 2

One dose · modeled timing

What an hCG timing estimate shows

100% = the model’s peak, not the dose left or a blood-test result.

About this curve

An injection does not produce an instant, flat level. This estimated curve shows the rise followed by the gradual fall.

Absorbed over time: The estimate is reconstructed from the study’s reported peak, peak time and half-life.
IU is the input: The full plotter takes hCG activity in IU. Syringe markings measure volume and are a different thing.

Estimate · Choriomon injected under the skin in women. Other products, use in men and repeated schedules are approximations. This shows hCG timing, not testosterone or fertility outcomes.

Model assumptions and sources

Why people add hCG to TRT

TRT and bodybuilding discussions focus on testicular shrinkage, plans for children and changes in libido or sexual sensation. Some people also consider hCG for post-cycle recovery. These are different goals, not one guaranteed package of benefits.

People report both positive sexual changes and anxiety, acne or uncomfortable hormone-related changes. Multiple drugs are often involved. A change in testicular size, libido or semen volume does not measure sperm production.

How it differs from testosterone

TRT supplies testosterone; hCG sends an LH-like signal to the testes to produce it. It is useful for selected men with deficient hormone signals, not every cause of low testosterone. Fertility treatment may also require FSH.

A small study found maintained semen measures with hCG alongside TRT. However, the AUA/ASRM guideline considers the evidence too limited to recommend adding hCG to exogenous testosterone as a fertility-preserving approach. Pregnancy plans call for a fertility assessment and review of the testosterone plan, not an assumption that an add-on protects fertility.

Product, units and purpose matter

Enter hCG activity in IU in this plotter. Syringe markings measure volume; they do not tell you the amount without the product concentration. Pregnyl’s labeled units and Ovidrel’s micrograms are not converted here.

Injection route and storage depend on the exact product. A multidose Pregnyl vial and single-use Zivafert do not share the same after-mixing instructions. Follow the product leaflet or pharmacy directions.

In women’s fertility treatment, hCG is a monitored trigger for final egg maturation or ovulation. That use is different from repeated male hormone treatment.

Effects to watch

Injection irritation, breast enlargement and fluid retention can occur. Severe pelvic pain, rapid weight gain or breathing trouble during ovarian stimulation need urgent assessment, as does a serious allergic reaction.

The chart estimates hCG timing, not testosterone levels, sperm production or pregnancy. Its study reference and extrapolations are in the model details.

Model details: HCG · estimated

How to read this estimate

Estimated from study endpoints; the curve between measurements is reconstructed. Compare amounts and timing in IU.

Based on urinary hCG injected under the skin in healthy women. Use for men, other products or repeated doses is an approximation. This shows hCG, not testosterone or fertility.

Assumptions, calculation and sources

Highly purified urinary hCG, Choriomon, subcutaneous injection. 24 healthy women aged 20–45 in a crossover pharmacokinetic analysis, with oral-contraceptive pituitary downregulation.

hCG: estimated concentration in serum (mIU/mL).

Calibration dose: 10000 IU
Reported calibration peak: 337.88 mIU/mL
Peak timing used: 16 hours
Terminal half-life used: 36.77 hours
Reconstructed absorption rate: 0.1473787 /hour

We reconstruct a one-compartment curve with first-order absorption and elimination from the reported peak, peak timing and terminal half-life; this is not a published fitted model.
The reported terminal half-life is used as the elimination half-life; absorption rate is inferred from the 16-hour peak timing.
Peak 337.88 IU/L at 10,000 IU is numerically 337.88 mIU/mL. The observed peak already includes absorption, so no additional bioavailability multiplier is applied.
Concentration scales linearly with entered IU; overlapping dose contributions are added when accumulation is enabled. Zero pre-existing hCG is assumed.
Applying this single-dose female study to men, other urinary products, lower doses or repeated schedules is an approximation, not verified equivalence.
Recombinant Ovidrel/Ovitrelle and intramuscular administration are outside this calibration. Their dose units and product instructions remain separate.
The curve estimates hCG, not testosterone, fertility, effectiveness, adverse effects or a suitable dose. Individual blood levels can differ substantially.
The default amount is a plotting example. The study used one 10,000-IU dose; other amounts and schedules are extrapolations.

Older hCG entries interpret each legacy mg as 10,000 IU, matching the original CSV assumption. Confirm the IU amount; this is not a mass-to-IU or preparation conversion.

Randomized urinary/recombinant hCG pharmacokinetic study (2022), Table 1
Choriomon 10,000 IU SC, N=24 PK analysis: arithmetic mean Cmax 337.88 IU/L, median Tmax 16 h, mean terminal half-life 36.77 h, observed mean AUCinf 23,779.06 IU·h/L. Endpoints are from the same product arm.
Trinchard-Lugan et al. 2002 — hCG pharmacokinetics
Study linked in the supplied CSV. Its abstract supports first-order absorption/one-compartment modelling after extravascular recombinant hCG. Used for the approximate curve structure, not urinary-product parameter calibration.

Estimate hcg-urinary-sc-2022-endpoint-estimate · version 1

Common questions

Does a return in testicular size mean hCG has restored fertility?

No. Size, blood testosterone and sperm production are different outcomes. Semen analysis checks sperm count and other features; even a satisfactory result cannot guarantee pregnancy.

Can I convert hCG IU to milligrams or syringe units?

There is no universal conversion for every product. IU measures biological activity, while milligrams measure mass. Syringe markings measure volume and require the exact prepared concentration. Do not treat those three units as interchangeable.

Can an hCG trigger cause a positive pregnancy test?

Yes. The UK Zivafert label warns that blood or urine pregnancy tests may be falsely positive for up to 10 days after the injection. Follow the fertility clinic’s testing schedule.

Is hCG effective for weight loss?

The FDA has not approved hCG for weight loss. It has not been shown to add weight loss beyond calorie restriction. Products sold as hCG diet drops, sprays or pellets are not approved substitutes for prescription injections.

Sources Labels, studies and notes behind this guide

Catalog evidence: Other human research. This describes the type of evidence, not a clinical review of every claim.

Summary and fact source checks: 2026-10-07. This records source checking, not medical review of the whole page.

Notes on the quick facts

Male hormone support: hCG acts like LH, one of the body’s reproductive hormones. This differs from supplying testosterone directly.
Fertility treatment: It can help restore sperm production when hormone signals are deficient. In women, it acts as a timed trigger after egg follicles have developed.
Main trade-offs: Injection-site discomfort, breast enlargement and fluid retention can occur. Maintaining testicular size does not by itself confirm fertility.

1. Pregnyl — U.S. prescribing information
U.S. label revised March 2025. Selected male hormone deficiencies, LH-like action, intramuscular route, adverse reactions and storage for the multiple-dose vial.
2. AUA/ASRM — Male Infertility Guideline, amended 2024
Pages 34–35: initial hCG treatment in idiopathic hypogonadotropic hypogonadism; FSH when indicated; limited evidence for preserving fertility by adding hCG to TRT.
3. Zivafert PFS — UK product information
April 2024 SmPC, sections 4.1–4.2: urinary hCG for ovulation induction and ART. Section 6: single-use vial; use immediately after mixing.
4. Hsieh et al. 2013 — hCG alongside testosterone therapy
Retrospective records of 26 hypogonadal men: hCG 500 IU intramuscularly every other day with testosterone therapy; mean follow-up 6.2 months. Follow-up is not a prescribed cycle length.
5. Urinary hCG study (2022), Table 1
Same Choriomon SC endpoints as the existing estimated model. Shape is normalized to its own peak; it is not a published fitted curve or a dosing recommendation.
6. Randomized urinary/recombinant hCG pharmacokinetic study (2022), Table 1
Choriomon 10,000 IU SC, N=24 PK analysis: arithmetic mean Cmax 337.88 IU/L, median Tmax 16 h, mean terminal half-life 36.77 h, observed mean AUCinf 23,779.06 IU·h/L. Endpoints are from the same product arm.
7. Trinchard-Lugan et al. 2002 — hCG pharmacokinetics
Study linked in the supplied CSV. Its abstract supports first-order absorption/one-compartment modelling after extravascular recombinant hCG. Used for the approximate curve structure, not urinary-product parameter calibration.
8. Urinary hCG SC estimate — 2022 study, Table 1
Estimated curve reconstructed from source endpoints. Enter IU; older stored mg fields retain the CSV encoding only, not a biological mass conversion.
9. Ovidrel — U.S. prescribing information
Recombinant hCG in a ready-to-use syringe, labeled in micrograms for subcutaneous administration. Does not provide a universal IU-to-mass conversion.
10. Radicioni et al. 2022 — urinary and recombinant hCG pharmacokinetics
Single-dose Choriomon under the skin in healthy women. Existing estimated curve and calibration remain unchanged; extrapolation to men and repeated schedules stays explicit.
11. FDA — hCG weight-loss products

Related compounds and examples

HCG