HCG FDA Approved

What It Is

Human chorionic gonadotropin (hCG) is a heterodimeric glycoprotein hormone produced naturally by the syncytiotrophoblast cells of the placenta during pregnancy. Its primary physiologic role in pregnancy is to rescue the corpus luteum from programmed regression, maintaining progesterone production in early gestation until the placenta takes over as the dominant progesterone source. hCG is the hormone detected by pregnancy tests — serum levels rise detectably within days of implantation and peak near the end of the first trimester.

Structurally, hCG is composed of two subunits: the α-subunit (92 amino acids), which is shared with LH, FSH, and TSH, and the β-subunit (145 amino acids), which confers receptor specificity. Both subunits are heavily glycosylated, and the unique hCG β-subunit C-terminal extension (a 28-amino-acid sequence not found in LH-β) is responsible for the compound's substantially longer circulating half-life — approximately 24–36 hours of biological activity versus 20 minutes for native LH.

Therapeutic hCG is available in two major formats. Urinary-derived hCG (Pregnyl by Organon, Novarel by Ferring) is purified from the urine of pregnant women and has been in clinical use since the 1930s. Recombinant choriogonadotropin alfa (Ovidrel by EMD Serono, ovitrelle in Europe) is produced via recombinant DNA technology in CHO cells and is chemically identical to the urinary-derived form but with higher purity and consistent batch-to-batch potency. Both bind the same LH/CG receptor and drive the same downstream signaling; the clinical choice is usually driven by indication, formulation convenience, and payer coverage.

In men's health, hCG's primary role is as an adjunct to testosterone replacement therapy (TRT). Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal (HPG) axis via negative feedback on the hypothalamus and pituitary, causing endogenous LH and FSH production to drop — which leads to reduced Leydig cell stimulation, testicular atrophy, cessation of intratesticular testosterone production, and spermatogenic arrest. Because hCG is an LH-receptor agonist, it replaces the missing LH signal at the testicular level, maintaining Leydig cell function, intratesticular testosterone (ITT) — which runs approximately 50–100-fold higher than serum testosterone and is essential for spermatogenesis — and testicular volume during TRT. Coviello et al. (J Clin Endocrinol Metab 2005; PMID 15713727) established the quantitative dose-response: 500 IU every-other-day SubQ maintained ITT at approximately 26% of pre-suppression levels during testosterone-induced gonadotropin suppression in healthy adults, versus <5% of baseline with testosterone alone.

Mechanism of Action

hCG's pharmacology is almost entirely captured by the statement that it is an LH-receptor agonist with substantially extended half-life relative to native LH. Downstream effects follow directly from LH/CG receptor signaling in target tissue.

• LH/CG receptor (LHCGR) agonism — hCG binds the LH/CG receptor, a G-protein-coupled receptor of the glycoprotein-hormone receptor family. Primary signaling is Gs-coupled, activating adenylyl cyclase → cAMP → PKA cascade. In males, LHCGR is expressed predominantly on testicular Leydig cells; in females, on theca cells and granulosa cells of the ovary and on corpus luteum cells.
• Steroidogenesis — Leydig cell — LHCGR → cAMP/PKA → activation of steroidogenic acute regulatory protein (StAR) → cholesterol transport into mitochondria → CYP11A1 cleavage of cholesterol to pregnenolone → cascade through 3β-HSD, CYP17A1, 17β-HSD to testosterone. Testosterone is the dominant Leydig-cell product; pregnenolone, DHEA, and progesterone are intermediates that spill out of the pathway at measurable levels.
• Intratesticular testosterone (ITT) maintenance — Normal ITT concentrations are approximately 50–100× serum testosterone due to the direct Leydig-to-seminiferous-tubule anatomical relationship and concentrating effects of androgen-binding protein. ITT of this magnitude is required to sustain spermatogenesis. Exogenous testosterone suppresses endogenous LH → collapses Leydig stimulation → ITT drops precipitously → spermatogenesis halts. hCG replaces the lost LH signal and preserves ITT (Coviello 2005; PMID 15713727).
• Testicular aromatase — intratesticular estradiol — Leydig cells express aromatase; LHCGR stimulation increases local aromatase activity and intratesticular estradiol. This contributes to the modest serum estradiol elevation some men experience on hCG and is relevant to aromatase inhibitor dosing in combined TRT+hCG protocols.
• Neurosteroids — pregnenolone, DHEA — Testicular steroidogenesis includes pregnenolone and DHEA as intermediates that spill out of the pathway. In men, Leydig cells are a measurable source of circulating pregnenolone and DHEA. TRT alone suppresses both; TRT + hCG largely preserves them. Some clinicians attribute subjective mood and cognitive benefits of TRT + hCG (versus TRT alone) to this preservation of neurosteroid precursors.
• Testicular volume preservation — Chronic LHCGR under-stimulation (as occurs in sustained exogenous testosterone use) produces Leydig-cell atrophy and reduced testicular volume (~20–40% volume loss over months). hCG co-administration largely prevents this — most men on TRT + adequate hCG (250–500 IU 2–3× weekly) maintain testicular volume near pre-TRT baseline.
• Ovulation induction — female use — In reproductive medicine, hCG is the "trigger shot" mimicking the mid-cycle LH surge that induces ovulation. Standard dosing for ovulation induction in ART protocols is a single 5,000–10,000 IU IM injection (or 250 mcg of Ovidrel recombinant) approximately 36 hours prior to planned ovum retrieval or intercourse.
• Cryptorchidism (pediatric) — In prepubertal boys with undescended testes of non-anatomic etiology, hCG courses (500–4,000 IU 2–3× weekly for 4 weeks) can stimulate testicular descent through Leydig-testosterone action on genital-tract anatomy. Surgical orchiopexy has largely supplanted this indication.
• FSH substitution not provided — hCG is LH-like but not FSH-like. Some advanced fertility protocols combine hCG with recombinant FSH or human menopausal gonadotropin (hMG) to reproduce both LH and FSH signaling in severely hypogonadotropic men.
• Leydig cell desensitization — theoretical at high dose — Chronic supraphysiologic LHCGR stimulation can induce receptor downregulation. At typical TRT-adjunct doses (250–500 IU 2–3× weekly), desensitization is not clinically significant. At bodybuilder-community doses (2,000–4,000 IU multiple times per week over extended periods) some clinicians have reported Leydig-cell tachyphylaxis requiring cycling.

What the Research Shows

The hCG evidence base spans multiple FDA-approved indications and decades of post-marketing data. The men's-health TRT-adjunct use case has smaller but mechanistically clean evidence.

• Intratesticular testosterone preservation (Coviello et al., J Clin Endocrinol Metab 2005; PMID 15713727) — Healthy adult men received GnRH antagonist acyline to suppress endogenous gonadotropins plus testosterone enanthate 200 mg/week, with or without varying doses of concurrent hCG (0, 125, 250, or 500 IU every other day). ITT measured via testicular fine-needle aspiration. Testosterone alone: ITT <5% of baseline. Testosterone + 500 IU hCG EOD: ITT ~26% of baseline. Dose-response is near-linear. The foundational paper anchoring modern TRT-plus-hCG protocols.
• Spermatogenesis preservation on TRT (Hsieh et al., J Urol 2013; PMID 23260550) — 26 hypogonadal men started TRT plus concurrent hCG (500 IU IM every other day); semen analyses measured at baseline and throughout TRT. Spermatogenesis was maintained in 100% of men on TRT + hCG; no patient became azoospermic during the follow-up. Practical clinical demonstration of the Coviello pharmacology.
• Hypogonadotropic hypogonadism (HH) fertility induction — hCG + recombinant FSH (or hMG) is established first-line therapy for fertility induction in men with congenital or acquired hypogonadotropic hypogonadism. Spermatogenesis induction rates of 60–90% over 6–24 months with this combined-gonadotropin protocol.
• Men's-health translational review (Lee & Ramasamy, Transl Androl Urol 2018; PMID 30050800) — Clinical review of hCG indications in male infertility and hypogonadism management; synthesizes the indication matrix for urology and reproductive endocrinology practice.
• Adolescent cryptorchidism (Ehrlich et al., older studies) — Multiple mid-20th-century studies established efficacy of hCG in stimulating testicular descent in prepubertal boys with non-anatomic cryptorchidism. Modern guidelines favor surgical orchiopexy as first-line, with hCG reserved for select cases.
• Ovulation induction — assisted reproduction — hCG as ovulation trigger is standard of care in IVF and timed-intercourse cycles; substantial literature supporting 5,000–10,000 IU urinary-hCG or 250 mcg recombinant choriogonadotropin alfa as ovulation trigger.
• Anabolic-steroid PCT context — hCG courses during post-cycle therapy (PCT) after anabolic-androgenic steroid cycles are used empirically to restart Leydig function, typically in 1,000–2,000 IU doses 2–3× weekly for 2–4 weeks, often with concurrent SERM (clomiphene, tamoxifen). Evidence base is observational / clinician experience rather than RCT.
• Obesity (Simeons diet — discredited) — The historical "HCG diet" claim that low-dose hCG enhances fat loss on a 500-kcal diet has been repeatedly disproven in controlled trials. The FDA issued a warning letter in 2011 against the homeopathic "HCG for weight loss" products. This use is not supported.

Human Data

hCG has been studied in humans for more than 80 years. The following are representative pivotal references across its major uses:

• Coviello et al., 2005 (PMID 15713727) — Quantitative dose-response of hCG 0–500 IU EOD on ITT during testosterone-induced gonadotropin suppression in healthy men. The foundational modern TRT-adjunct paper.
• Hsieh et al., 2013 (PMID 23260550) — Prospective cohort of 26 hypogonadal men on TRT + concomitant IM hCG; 100% maintained spermatogenesis.
• Lee & Ramasamy, 2018 (PMID 30050800) — Indications review: hypogonadism, male infertility, fertility preservation.
• Ovulation-induction RCTs (multiple, 1990s–2010s) — Established recombinant choriogonadotropin alfa 250 mcg as equivalent to urinary hCG 5,000–10,000 IU for ovulation trigger; FDA approval basis for Ovidrel (2000).
• Hypogonadotropic hypogonadism fertility-induction trials — Multiple multicenter open-label studies and retrospective cohorts establishing hCG + FSH as the standard approach; sperm-induction rates 60–90% over 6–24 months.
• Kaminetsky et al., BJU Int 2014 (PMID 24127760) — RCT of enclomiphene citrate in obese hypogonadal men demonstrating testosterone rise with preserved fertility — adjacent mechanism (SERM-based axis restoration) relevant to the HCG-vs-SERM decision point in men wanting to preserve fertility without direct testicular stimulation.
• FDA 2020 reclassification context — In March 2020, the FDA reclassified hCG from a drug to a biologic under the Biologics Price Competition and Innovation Act (BPCIA). The reclassification moved hCG from the 505(b) drug pathway to the 351 biologics pathway and constrained 503A compounding access to hCG, which had previously been common for customized men's-health protocols.
• Safety databases — Decades of FDA Adverse Event Reporting System (FAERS) data for Pregnyl and Novarel; well-characterized side-effect profile dominated by local injection reactions and dose-dependent estradiol-mediated effects.

Dosing from the Literature

hCG dosing is indication-specific and well-defined by decades of clinical use. The following synthesizes approved and community-standard protocols.

Reconstitution & Storage

hCG is supplied as a lyophilized powder with a matched diluent (bacteriostatic saline or sterile water), or — in the case of Ovidrel — as a prefilled subcutaneous syringe. The urinary-derived products (Pregnyl, Novarel) require reconstitution at the point of first use.

• Reconstitution — Inject diluent slowly down the vial wall at 45°. Swirl gently until clear; do not shake. The solution should be clear and colorless.
• Storage — lyophilized — Refrigerated at 2–8°C. Do not freeze. Shelf life per manufacturer labeling (typically 2 years unopened).
• Storage — reconstituted — Refrigerated at 2–8°C. Stable for 30–60 days per most manufacturer labels (varies by product). Use bacteriostatic water (benzyl alcohol preserved) for multi-dose vials to extend stability.
• Injection route — Subcutaneous is standard for the TRT-adjunct use case; IM is the route specified in most FDA-approved indications. Both are effective; SubQ is more convenient and has slightly slower absorption.
• Needle / syringe — 29G–31G insulin syringes for SubQ; 22G–25G for IM (pediatric cryptorchidism or ovulation-trigger IM use).
• Inspection — Discard if cloudy, discolored, or with particulate matter.

→ Use the Kalios Dosing Calculator for exact syringe units by IU

Side Effects & Risks

• Estradiol elevation — LHCGR activation increases intratesticular aromatase; some men experience measurable serum estradiol elevation (symptomatic: water retention, nipple sensitivity, mood changes, mild gynecomastia). Dose-dependent. May require aromatase inhibitor (anastrozole) adjustment in combined TRT+hCG protocols.
• Gynecomastia — Can develop if estradiol rises meaningfully without management. Monitoring and AI dose adjustment prevent this in most men; rarely progresses to surgical indication when protocol is properly managed.
• Injection-site reactions — Mild local redness, induration, or pain. More common with IM than SubQ.
• Headache — Occasionally reported, typically mild and self-limiting.
• Mood changes — Some users report irritability, mood swings, or mild emotional lability — most often related to the estradiol swings rather than hCG itself. Tends to stabilize with AI titration.
• Fluid retention — Mild peripheral edema at higher doses; estradiol-mediated.
• OHSS (ovarian hyperstimulation syndrome) — female ovulation-induction context — Serious risk of hCG use in ovulation induction in women; can be life-threatening. Requires close monitoring by reproductive endocrinology. Not applicable to male use at TRT-adjunct doses.
• Multiple gestation — female fertility context — hCG ovulation induction increases risk of twin / multiple gestation pregnancies. Monitored in reproductive-medicine practice.
• Leydig cell desensitization (theoretical, high-dose chronic) — Chronic supraphysiologic LHCGR stimulation can induce receptor downregulation. At standard TRT-adjunct doses (250–500 IU 2–3× weekly), not clinically significant. At bodybuilder-community doses (2,000+ IU multiple times weekly chronically), some clinicians report tachyphylaxis requiring dose cycling.
• Prostate concerns — hCG-driven increases in testosterone and estradiol theoretically increase prostate growth potential; standard TRT prostate monitoring (PSA, DRE) applies.
• Thromboembolic risk (rare) — Case reports of thromboembolic events with high-dose hCG in ovulation-induction contexts; not clinically significant at TRT-adjunct doses.
• Cardiovascular (indirect) — Testosterone-driven hematocrit elevation standard TRT monitoring still applies when TRT + hCG is used; hCG itself does not directly affect hematocrit.
• Hypersensitivity — Rare allergic reactions to urinary-derived products (contaminant proteins). Recombinant Ovidrel has a cleaner purity profile.
• WADA status — males — hCG is specifically prohibited in male athletes at all times under WADA code S2 (peptide hormones, growth factors, related substances and mimetics). Females may use hCG for obstetric or reproductive indications per their sport's medical certification. Male athletes subject to anti-doping testing cannot use hCG.

Bloodwork & Monitoring

Monitoring for hCG use is straightforward and tightly integrated with TRT monitoring when used as a TRT adjunct.

• Total and free testosterone — Confirm adequate testosterone in TRT-adjunct use. hCG alone can produce meaningful testosterone elevation in secondary hypogonadism; in TRT adjunct, serum testosterone is primarily driven by exogenous testosterone.
• Estradiol (sensitive LC-MS/MS assay) — Critical. hCG increases intratesticular aromatase activity and can elevate serum estradiol. Use the sensitive (LC-MS/MS) assay, not the standard immunoassay, which over-reads in males.
• LH and FSH — Suppressed during TRT regardless of hCG. Useful for baseline pre-TRT assessment and for confirming HPG axis recovery post-cycle in PCT context.
• Semen analysis — If fertility preservation is a protocol goal, periodic semen analyses (every 3–6 months initially, then annually) confirm ongoing spermatogenesis.
• Hematocrit and CBC — Standard TRT monitoring. hCG itself does not raise hematocrit; the testosterone it supports does.
• PSA (men >40) — Baseline and at 6–12 month intervals per urology guidelines.
• Lipid panel — Standard TRT monitoring.
• HbA1c and fasting glucose — Standard metabolic monitoring.
• Pregnancy test (females) — Exclude pregnancy before any non-reproductive-medicine use.

Commonly Stacked With

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Regulatory Status

Related Compounds

Compounds that work upstream, downstream, or alongside hCG in the HPG axis.

Next Steps

Key References

1. Coviello AD, Matsumoto AM, Bremner WJ, Herbst KL, Amory JK, Anawalt BD, Sutton PR, Wright WW, Brown TR, Yan X, Zirkin BR, Jarow JP. Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression. J Clin Endocrinol Metab. 2005;90(5):2595-2602. PMID: 15713727.
2. Hsieh TC, Pastuszak AW, Hwang K, Lipshultz LI. Concomitant intramuscular human chorionic gonadotropin preserves spermatogenesis in men undergoing testosterone replacement therapy. J Urol. 2013;189(2):647-650. PMID: 23260550.
3. Lee JA, Ramasamy R. Indications for the use of human chorionic gonadotropic hormone for the management of infertility in hypogonadal men. Transl Androl Urol. 2018;7(Suppl 3):S348-S352. PMID: 30050800.
4. Kaminetsky J, Werner M, Fontenot G, Wiehle RD. Oral enclomiphene citrate stimulates the endogenous production of testosterone and sperm counts in men with low testosterone: comparison with testosterone gel. J Sex Med. 2013;10(6):1628-1635. PMID: 23530575. (Adjacent SERM-based axis-restoration evidence; informs the hCG-vs-SERM decision in men preserving fertility.)
5. Rastrelli G, Corona G, Mannucci E, Maggi M. Factors affecting spermatogenesis upon gonadotropin-replacement therapy: a meta-analytic study. Andrology. 2014;2(6):794-808. PMID: 25099686. (Meta-analysis of spermatogenesis response to gonadotropin replacement — relevant to hCG/FSH combined fertility induction.)
6. U.S. Food and Drug Administration. Pregnyl (chorionic gonadotropin) Prescribing Information. Organon USA Inc.
7. U.S. Food and Drug Administration. Novarel (chorionic gonadotropin) Prescribing Information. Ferring Pharmaceuticals.
8. U.S. Food and Drug Administration. Ovidrel (choriogonadotropin alfa) Prescribing Information. EMD Serono. First approved 2000.
9. U.S. Food and Drug Administration. FDA reclassification of HCG as a biologic under the Biologics Price Competition and Innovation Act (BPCIA). March 23, 2020 effective date.
10. Ramasamy R, Armstrong JM, Lipshultz LI. Preserving fertility in the hypogonadal patient: an update. Asian J Androl. 2015;17(2):197-200. PMID: 25652635.
11. Bhasin S, Brito JP, Cunningham GR, Hayes FJ, Hodis HN, Matsumoto AM, Snyder PJ, Swerdloff RS, Wu FC, Yialamas MA. Testosterone Therapy in Men With Hypogonadism: An Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. PMID: 29562364. (Society practice guideline framing TRT adjuncts including hCG.)
12. Crosnoe LE, Grober E, Ohl D, Kim ED. Exogenous testosterone: a preventable cause of male infertility. Transl Androl Urol. 2013;2(2):106-113. PMID: 26813847. (Mechanism and clinical framing of TRT-induced infertility and hCG-based prevention.)
13. WADA. 2026 World Anti-Doping Code Prohibited List. Section S2 — Peptide hormones, growth factors, related substances, and mimetics. World Anti-Doping Agency. (hCG specifically prohibited in males.)
14. Shiraishi K, Matsuyama H. Gonadotoropin actions on spermatogenesis and hormonal therapies for spermatogenic disorders. Endocr J. 2017;64(2):123-131. PMID: 28100858.
15. Dubey A, Jalali M, Fauzdar A, Hargreave TB. The efficacy of different protocols of hCG administration in hypogonadotrophic hypogonadism. Clin Endocrinol (Oxf). 2007;67(3):389-395. (Dual-gonadotropin fertility-induction protocol evidence.)
16. Swerdloff RS, Wang C. The testis and male hypogonadism, infertility, and sexual dysfunction. In: Goldman-Cecil Medicine. 26th ed. Elsevier. (Standard clinical reference for HPG-axis pharmacology and hCG use.)