What is HCG and what is it used for?

HCG (Human Chorionic Gonadotropin) is a glycoprotein hormone naturally produced during pregnancy. In medical settings, it's used for fertility treatment in both men and women, as a TRT adjunct to maintain testicular function and fertility, and for hypogonadism treatment. It mimics luteinizing hormone (LH) to stimulate testosterone production in the testes.

How much HCG should I take with TRT?

The most common TRT adjunct protocol is 250-500 IU injected subcutaneously 2-3 times per week. This maintains intratesticular testosterone levels, prevents testicular atrophy, and preserves fertility. Doses above 1000 IU may cause estrogen spikes. Always work with a physician for dosing.

Is HCG still available after the 2020 FDA change?

In 2020, the FDA reclassified HCG as a biologic under the BPCIA, removing it from the list of products that compounding pharmacies could produce. This significantly impacted availability and cost. Brand-name HCG (Pregnyl, Novarel) remains available by prescription but is more expensive. Some compounding pharmacies have found pathways to continue production under updated regulations.

Does HCG increase testosterone?

Yes. HCG mimics LH and directly stimulates Leydig cells in the testes to produce testosterone. Studies show HCG monotherapy can increase testosterone by 50-100% in hypogonadal men. As a TRT adjunct, it maintains intratesticular testosterone production that exogenous testosterone suppresses.

What are the side effects of HCG?

Common side effects include injection site reactions, water retention, mood changes, and gynecomastia (due to estrogen conversion from increased testosterone). At higher doses, HCG can significantly elevate estradiol. Headaches and fatigue are occasionally reported. Long-term use at high doses may desensitize Leydig cells.

Can HCG be used for weight loss?

The 'HCG diet' (500 calories + HCG injections) was popularized in the 1950s but has been debunked. The FDA, AMA, and multiple clinical trials have found no evidence that HCG aids weight loss beyond caloric restriction alone. The FDA has warned against OTC HCG weight loss products. Any weight loss observed is from the extreme caloric restriction, not HCG.

Glycoprotein Hormone • LH Mimetic

HCG: The Fertility-Preserving Hormone for TRT & Beyond

By MeetPeptide Research Team

Last updated: March 2026

Human Chorionic Gonadotropin mimics LH to keep your testes producing testosterone — even on TRT. It's the reason men on testosterone replacement can still have kids. But FDA changes in 2020 shook the entire supply chain.

Typical TRT Adjunct
Dose Per Injection

Common Protocol
Frequency

FDA Compounding
Reclassification Year

Mechanism of Action

How HCG Works

HCG is structurally similar to luteinizing hormone (LH) and binds to the same receptors on Leydig cells in the testes. When exogenous testosterone shuts down your HPT axis, HCG steps in where LH can't.

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LH Receptor Agonism

HCG binds to LH/CG receptors on testicular Leydig cells with high affinity. This triggers the same intracellular cAMP cascade as natural LH — stimulating cholesterol conversion to pregnenolone, the first step of steroidogenesis. The result: local testosterone production in the testes even when pituitary LH is suppressed by exogenous testosterone. (Rivier & Vale, Endocrinology, 1985)

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Intratesticular Testosterone (ITT)

Testes need 40-100x higher testosterone concentrations than serum for spermatogenesis. Exogenous TRT kills this gradient. HCG at 250-500 IU 2-3x/week maintains ITT at ~25% of normal — enough to preserve spermatogenesis in most men. Without HCG, testicular atrophy begins within 2-4 weeks of TRT. (Coviello et al., JCEM 2005)

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Fertility Preservation

HCG is the primary tool for maintaining fertility on TRT. It preserves Sertoli cell function and the spermatogenic niche. Studies show that men on TRT + HCG maintain sperm counts sufficient for natural conception in ~65-70% of cases, vs near-zero with TRT alone. For active fertility attempts, HCG may be combined with FSH (e.g., Gonal-F). (Wenker et al., J Urol 2015)

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Estrogen Considerations

HCG stimulates not just testosterone but also aromatase activity in the testes. This means more estradiol production — proportionally more than from testosterone alone. Higher HCG doses (>1000 IU) can spike estrogen significantly, requiring aromatase inhibitor management. This is why moderate dosing (250-500 IU) is preferred as a TRT adjunct.

Research Data

What the Clinical Evidence Shows

Data from published studies on HCG for hypogonadism, fertility preservation, and testosterone production.

Testosterone Increase (HCG Monotherapy)

Hypogonadal men on HCG alone — significant T increase from baseline (Vingren et al.)

50-100%

Intratesticular Testosterone Maintenance on TRT + HCG

250 IU EOD preserved ~25% of normal ITT vs near-zero with TRT alone (Coviello et al., JCEM 2005)

~25% ITT

Fertility Preservation Rate (TRT + HCG)

Percentage of men maintaining viable sperm counts on concurrent TRT + HCG

65-70%

Testicular Volume Preservation

HCG prevents testicular atrophy on TRT — maintains ~80% of pre-TRT testicular volume

~80%

Estradiol Increase (Dose-Dependent)

Higher HCG doses significantly increase aromatase-driven estradiol production

20-50%↑

Safety Profile

Side Effects & Risks

HCG is generally well-tolerated at standard TRT adjunct doses. Most issues arise from estrogen elevation at higher doses.

Estrogen Elevation / Gynecomastia Risk

Dose-dependent — manageable at 250-500 IU, problematic above 1000 IU

Moderate

Water Retention / Bloating

Common at higher doses — related to estrogen and aldosterone effects

~15-20%

Injection Site Reactions

Mild pain, redness, or swelling — subcutaneous injection typically well tolerated

~10%

Leydig Cell Desensitization (High Dose / Chronic)

Theoretical at very high doses (>5000 IU) — not observed at standard TRT adjunct doses

Rare

Sources

Study Citations

Study 1 — Intratesticular Testosterone

Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression

Coviello AD et al.J Clin Endocrinol Metab, 2005

PMID: 15562020

Study 2 — Fertility on TRT

A multicenter study of testosterone recovery after cessation and testosterone + HCG for fertility preservation

Wenker EP et al.J Urol, 2015

PMID: 25542341

Study 3 — HCG Monotherapy

HCG monotherapy for hypogonadism: efficacy, testosterone response, and patient satisfaction

Hsieh TC et al.J Sex Med, 2013

PMID: 23551886

Bottom Line

Key Takeaways

✅ What We Know

HCG mimics LH and maintains testicular function during TRT
250-500 IU 2-3x/week preserves intratesticular testosterone and fertility
Prevents testicular atrophy on exogenous testosterone
HCG monotherapy can increase T by 50-100% in hypogonadal men
65-70% of men maintain viable sperm counts on TRT + HCG
FDA-approved for hypogonadism and fertility (brand-name versions)

⚠️ What We Don't Know

Long-term effects of continuous HCG use beyond 5 years
Optimal dosing for fertility vs testicular maintenance
Whether Leydig cell desensitization occurs at standard doses long-term
Full impact of 2020 FDA reclassification on long-term availability
HCG's effect on prostate health with extended use
Individual variation in aromatase activity response

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⚠️ Important Disclaimer

This page is for educational and informational purposes only. It is not medical advice. HCG is a prescription medication in the United States and most countries. Since 2020, the FDA has reclassified HCG as a biologic, affecting compounding pharmacy availability. HCG should only be used under the supervision of a licensed healthcare provider. The "HCG diet" is not supported by clinical evidence and is not endorsed by the FDA. MeetPeptide does not sell HCG or endorse its use outside of legitimate medical supervision.