Human Chorionic Gonadotropin

Testosterone replacement therapy (exogenous testosterone) suppresses pituitary LH production to near zero via negative feedback. With LH absent, Leydig cells lose their primary stimulatory signal. The consequences: (1) intratesticular testosterone collapses (94% reduction in some human studies), impairing spermatogenesis — men on TRT without hCG are typically azoospermic or severely oligospermic; (2) testicular volume decreases — the physical shrinkage (atrophy) associated with TRT is primarily due to Leydig cell and Sertoli cell dormancy; (3) the testicular steroidogenic infrastructure degrades over months to years, making recovery after TRT discontinuation progressively more difficult. hCG prevents all three consequences by directly maintaining Leydig cell activity throughout TRT.

Standard TRT + hCG protocol: hCG 250-500 IU SubQ 2-3x/week administered concurrently with testosterone therapy. The LH-equivalent signal hCG provides is sufficient to maintain testicular volume, ITT, and spermatogenesis in most men. Clinical evidence: Lee 2018 [1] (Translational Andrology and Urology) reviewed the evidence — hCG is safe and efficacious for preserving fertility during testosterone therapy; maintains spermatogenesis; most studies show sperm count preservation with 250-500 IU 2-3x/week. Higher doses (>500 IU per injection) increase estrogen production via aromatization in the testes, potentially requiring aromatase inhibitor management. Standard clinical practice: start at 250 IU EOD or 3x/week; titrate based on ITT preservation (indirectly estimated by sperm parameters) and estradiol labs.

THE CRITICAL PCT SEQUENCING MISTAKE — HCG ALONE DOES NOT RESTORE THE HPG AXIS

Using hCG as PCT monotherapy — a practice common in the anabolic steroid community before the 1990s — is counterproductive for HPG axis restoration. hCG is an LH mimetic: while it stimulates Leydig cells to produce testosterone, it also suppresses pituitary LH production via the same negative feedback mechanism as endogenous testosterone. Taking hCG alone post-cycle raises testosterone (good) but prevents the pituitary from resuming its own LH production (bad). The body 'sees' hCG's testosterone signal the same way it sees exogenous testosterone — the HPG axis remains suppressed as long as hCG is present. The modern PCT protocol uses a two-phase approach: Phase 1 (hCG phase): 1,000-2,500 IU hCG EOD for 10-14 days to prime and reactivate Leydig cells before they can respond to restored endogenous LH. Phase 2 (SERM phase): After hCG is stopped, SERMs (clomiphene 50mg/day or tamoxifen 20mg/day) block pituitary estrogen receptors, restoring GnRH and LH pulsatility, allowing the reactivated testes to respond to the body's own LH. The phases must be sequential — hCG and SERMs simultaneously is also problematic because hCG's testosterone-raising effect suppresses LH recovery during SERM therapy.

Phase

Duration

Compounds

Doses

Purpose

Pre-PCT / End of Cycle

Last 4-6 weeks of AAS cycle

HCG during cycle (if not already on-cycle hCG)

250-500 IU SubQ 2-3x/week

Prevent testicular atrophy; prime Leydig cells before PCT begins

Phase 1: hCG blast (off-cycle)

10-14 days

hCG

1,000-2,500 IU SubQ every other day

Reactivate dormant Leydig cells; restore testicular volume and steroidogenic capacity

Transition (washout)

~3 days after last hCG injection

None

—

Allow hCG to clear; HPG axis no longer suppressed by hCG before SERMs begin

Phase 2: SERM therapy

4-6 weeks

Clomiphene (Clomid) 50 mg/day OR Tamoxifen (Nolvadex) 20 mg/day

Taper over weeks 5-6

Block pituitary estrogen receptors → restore GnRH/LH pulsatility → sustain Leydig cell stimulation from endogenous LH

Monitoring

Throughout PCT and 4 weeks post-PCT

Bloodwork: testosterone, LH, FSH, estradiol, SHBG

—

Confirm recovery; guide protocol adjustment if needed

An alternative to the post-cycle hCG blast is continuous low-dose hCG throughout the anabolic steroid cycle (on-cycle hCG). By maintaining Leydig cell activity throughout the cycle, the atrophy problem is prevented rather than corrected. Leydig cells that have never been dormant are faster to respond to endogenous LH recovery than cells that have been inactive for months. Standard on-cycle protocol: 250-500 IU SubQ 2x/week. This approach eliminates the 'testicular reactivation' phase of PCT — the testes are already functional when the cycle ends, making SERM-phase recovery faster and more complete. The tradeoff: additional estrogen management may be needed, as on-cycle hCG adds to the testosterone-derived aromatization that occurs during AAS use.

Human chorionic gonadotropin is a heterodimeric glycoprotein — two non-covalently linked subunits. The α-subunit (92 amino acids, ~14 kDa before glycosylation) is identical to the α-subunit of LH, FSH, and TSH — all four hormones share this common subunit. The β-subunit (145 amino acids, ~22 kDa before glycosylation) is unique to hCG and is what gives hCG its specificity. The hCG β-subunit includes a 24-amino acid C-terminal peptide (CTP) extension that LH's β-subunit lacks. This CTP extension is heavily glycosylated with four O-linked oligosaccharide chains and is the structural basis for hCG's extended half-life compared to LH. Total molecular weight: approximately 36,000-40,000 Da depending on glycosylation. The degree of glycosylation varies between isoforms; hyperglycosylated hCG is associated with specific biological activities and is the predominant form in early pregnancy.

Parameter

hCG

LH

Half-life

~36 hours

~30 minutes

Receptor (LHCGR)

3x higher binding affinity

Standard LH binding affinity

Structure

α-subunit (shared) + unique β-subunit with CTP extension

α-subunit (shared) + β-subunit without CTP

Therapeutic dosing

Once or twice weekly

Continuous infusion or multiple daily injections required to replicate LH pulsatility

Clinical utility

Ideal for pharmacological Leydig cell stimulation

Not practical as a therapeutic LH replacement (too short-acting)

Detection

Easily detected by immunoassay targeting β-subunit; unmistakable in male urine

Endogenous; not a useful doping marker

The 36-hour half-life of hCG vs LH's 30 minutes reflects the CTP extension's protective effect against renal clearance and plasma peptidase degradation. From a pharmacological standpoint, this makes hCG a dramatically more useful LH mimetic than LH itself: a single SubQ injection of 500 IU hCG maintains supraphysiological Leydig cell stimulation for approximately 2-3 days, while an equivalent LH dose would be cleared within hours. This is why hCG became the pharmacological tool of choice for LH-replacement therapy in both fertility medicine and testosterone restoration — it solves the pharmacokinetic problem that LH's very short half-life creates for therapeutic use.

hCG detection in anti-doping: the β-subunit of hCG is the specific target of immunoassay testing. In males, endogenous hCG production is essentially zero under non-pathological conditions — any measurable hCG in male urine is presumptive evidence of exogenous administration. In females, endogenous hCG elevation is normal during pregnancy; anti-doping testing of female athletes must account for this. The detection window for hCG after SubQ injection: several days to a week or more depending on dose. For WADA-tested athletes, the use of hCG for any purpose — including legitimate physician-prescribed fertility or hypogonadism treatment — requires a Therapeutic Use Exemption (TUE).

LHCGR (LH/hCG receptor) is a Gs-coupled receptor expressed on: Leydig cells of the testes (testosterone production); ovarian theca cells (androgen production for estrogen synthesis); luteinized granulosa cells (progesterone production); placental cytotrophoblasts. hCG binding to LHCGR → Gs coupling → adenylate cyclase activation → cAMP → PKA activation → StAR protein phosphorylation → cholesterol transport into mitochondria → CYP11A1 (cholesterol side-chain cleavage enzyme) → pregnenolone → testosterone synthesis cascade. The pathway from LHCGR activation to testosterone production is well-characterized and identical for both hCG and LH, with hCG producing a more prolonged and higher-amplitude stimulation per injection due to its extended half-life.

The hypothalamic-pituitary-gonadal (HPG) axis operates by negative feedback: hypothalamus releases GnRH in pulses → anterior pituitary releases LH and FSH → testes produce testosterone and sperm → testosterone feeds back to hypothalamus and pituitary to reduce GnRH and gonadotropin secretion → testosterone production self-regulates within physiological range. Exogenous testosterone administration (TRT or anabolic steroids) delivers testosterone to the circulation from outside this feedback loop. The elevated circulating testosterone suppresses hypothalamic GnRH and pituitary LH/FSH production via negative feedback — just as endogenous testosterone would at high levels. The consequence: with LH suppressed, Leydig cells receive no stimulation; they become dormant; testicular volume decreases (testicular atrophy); intratesticular testosterone plummets; spermatogenesis collapses.

hCG bypasses the suppressed pituitary entirely. By directly stimulating LHCGR on Leydig cells, hCG provides the LH-equivalent signal to the testes regardless of whether the pituitary is producing LH or not. The Leydig cells do not distinguish between LH and hCG at the receptor level — both ligands activate LHCGR and trigger the same testosterone production cascade. During exogenous testosterone administration, LH is suppressed to near zero; but intratesticular testosterone can be maintained at levels sufficient for spermatogenesis by concurrent hCG administration, because hCG directly restores the Leydig cell stimulation that LH is no longer providing.

THE INTRATESTICULAR TESTOSTERONE CONCEPT — THE MOST IMPORTANT CLINICAL PRINCIPLE

Circulating serum testosterone (what a blood test measures) and intratesticular testosterone (ITT) — the concentration within the testes — are different compartments with different concentrations and different biological significance. Normal ITT is approximately 50-100x higher than serum testosterone. This high ITT concentration is required for spermatogenesis; the Sertoli cells supporting sperm production need extremely high local testosterone concentrations. Exogenous testosterone suppresses LH, which collapses ITT dramatically (up to 94% reduction in some studies) even while serum testosterone may be at normal or supraphysiological levels. This is why men on TRT without hCG often experience spermatogenesis failure and infertility — their serum T looks fine, but their ITT is functionally zero. hCG restores ITT by directly stimulating Leydig cells to produce testosterone locally within the testes. The serum testosterone from hCG is a secondary effect; the restoration of ITT is the primary therapeutic mechanism for fertility preservation.

In women undergoing controlled ovarian stimulation (COS) for in vitro fertilization (IVF) or intrauterine insemination (IUI), the final maturation of oocytes and triggering of ovulation is typically achieved by administration of hCG — the 'trigger shot.' This application mimics the physiological LH surge that triggers ovulation at mid-cycle. In IVF cycles, hCG is administered 34-36 hours before oocyte retrieval; the 36-hour half-life allows precise timing of retrieval. Common doses: 5,000-10,000 IU of urinary hCG (Pregnyl, Novarel) or 250 mcg of recombinant hCG (choriogonadotropin alfa, Ovidrel). This is one of the most commonly administered prescription drugs in reproductive medicine.

Undescended testicle(s) in prepubertal boys. hCG stimulates testosterone production, which in some cases provides sufficient hormonal stimulus to facilitate testicular descent. Standard protocols: 1,000-5,000 IU per injection, 2x/week for several weeks. Success rates are variable and less reliable than surgical orchiopexy; surgery is the preferred definitive treatment for most cases. hCG is sometimes used as a diagnostic tool (the 'hCG stimulation test') to confirm the presence and steroidogenic function of testicular tissue in boys with suspected bilateral anorchia.

Hypogonadotropic hypogonadism (HH) — low testosterone secondary to inadequate pituitary LH production (not due to testicular failure). Causes include Kallmann syndrome, pituitary adenoma, pituitary surgery, radiation, or other hypothalamic/pituitary pathology. hCG therapy directly replaces the deficient LH signal to the testes: standard doses of 1,000-4,000 IU 3x/week, titrated to testosterone response. For men with HH who desire fertility: hCG provides both the testosterone restoration and the ITT required for spermatogenesis. If hCG monotherapy is insufficient for full spermatogenesis restoration, FSH (follitropin or menotropins) is added.

A diagnostic test assessing Leydig cell functional reserve: a standard dose of hCG is administered; testosterone is measured before and 72-96 hours after. An adequate testosterone rise confirms functional Leydig cells capable of responding to LH-equivalent stimulation. Used in: assessing testicular function in males with suspected hypogonadism; confirming presence of testicular tissue in prepubertal cryptorchidism; evaluating potential for testosterone recovery in men with severe AAS-induced hypogonadism before embarking on PCT.

Albert T.W. Simeons, a British endocrinologist working in Rome, published 'Pounds and Inches: A New Approach to Obesity' in 1954. His protocol: daily injections of 125 IU hCG plus a very-low-calorie diet of exactly 500 calories per day, for 26-40 days. He claimed: hCG caused preferential mobilization of 'abnormal fat deposits' (hips, thighs, buttocks); hCG suppressed hunger, making the 500-calorie diet comfortable to maintain; hCG 'reset' a metabolic regulatory center, permanently changing eating patterns. Simeons reportedly observed that boys treated with hCG for Frohlich's syndrome (a gonadotropin deficiency with obesity) showed appetite reduction and fat loss — from this clinical observation he extrapolated the weight-loss hypothesis. His results were not replicated by others; when other researchers noted this, he argued that only he understood how to implement the protocol correctly.

THE EVIDENCE — 14 RANDOMIZED CONTROLLED TRIALS, ONE CONCLUSION

A meta-analysis of 14 randomized double-blind controlled trials of hCG for weight loss was completed by 1995. The conclusion was emphatic: there is no evidence that hCG is effective in the treatment of obesity; it does not bring about weight loss or fat redistribution beyond that resulting from a very-low-calorie diet alone; it does not reduce hunger or increase the sense of well-being beyond the caloric restriction itself. Every single RCT found that subjects on hCG + 500-calorie diet lost the same amount of weight as subjects on placebo + 500-calorie diet. The only active ingredient in the Simeons diet was the 500-calorie restriction — which was, and remains, a starvation-level intake that produces rapid weight loss regardless of any co-administered hormone.

The FDA's position on hCG and weight loss has been stated clearly in multiple documents: (1) In the official prescribing information for hCG injection (Pregnyl, Novarel), the following statement appears: 'There is no substantial evidence that it increases weight loss beyond that resulting from caloric restriction, that it causes a more attractive or normal distribution of fat, or that it decreases the hunger and discomfort associated with calorie-restricted diets.' This language is in the label of the FDA-approved product. (2) The FDA declared it illegal to sell OTC products containing hCG for weight loss. (3) FDA and FTC jointly issued warning letters to seven companies marketing homeopathic hCG weight-loss products in 2011, threatening enforcement action for violation of the Federal Food, Drug, and Cosmetic Act. (4) The FDA website explicitly states: 'HCG is not approved without a prescription and is not approved for weight loss.'

'Homeopathic hCG' products — drops, sprays, and pellets sold OTC — represent a fraud compounded on top of a fraud. Homeopathic preparations use serial dilutions so extreme that no molecules of the original substance remain in the final product. A homeopathic hCG product contains no hCG at all. This means: (1) the underlying claim (that hCG causes weight loss beyond caloric restriction) is false; and (2) the product doesn't even contain the compound it claims. Additionally, hCG is a large glycoprotein (MW ~36-40 kDa) — even if a sublingual or oral product contained actual hCG, it would be entirely degraded by GI peptidases before any systemic absorption. Oral hCG cannot work pharmacologically even in principle. OTC homeopathic hCG is doubly fraudulent: the claim is false, and the product doesn't even contain what it claims.

The Simeons protocol had largely faded by the 1970s, discredited by clinical trials. Its resurgence in the 2000s was driven primarily by Kevin Trudeau — a serial infomercial fraudster who had previously been subject to FTC consent orders for false advertising. His 2007 book 'The Weight Loss Cure They Don't Want You to Know About' promoted the Simeons hCG protocol to millions. The book was misleading in multiple ways documented by the FTC, which charged Trudeau with misrepresentation. Courts found that Trudeau violated multiple consent orders by claiming the diet was 'easy' and 'approved by the FDA.' He ultimately received a 10-year federal prison sentence in 2014. Despite this, the hCG diet market generated hundreds of millions of dollars in revenue and continues to operate through physician-prescribing networks and internet supplement sales.

hCG at doses used for fertility, hypogonadism treatment, and PCT (250-5,000 IU per injection) has a generally favorable safety profile based on decades of clinical use. The most important side effects in the male context: estrogen elevation — hCG stimulates Leydig cell testosterone production, and testosterone aromatizes to estradiol; at doses above 500 IU per injection, estrogen elevation can become clinically significant; gynecomastia, water retention, mood changes, and reduced libido from estrogen dominance are the primary concerns; aromatase inhibitor (anastrozole 0.25-0.5 mg 2x/week) may be needed at higher doses. LHCGR desensitization — at very high continuous doses (above the typical therapeutic range), chronic stimulation can cause LHCGR downregulation, reducing Leydig cell responsiveness; this is the rationale for keeping PCT hCG courses short (10-14 days) and for not using hCG continuously at high doses for extended periods. Injection site reactions (typical; mild). Headache (occasional).

ACTIVE MALIGNANCY — CONTRAINDICATION AND TUMOR MARKER STATUS

hCG carries a specific active malignancy contraindication that is more complex than the generic 'growth factor concern' that applies to GH secretagogues. First, hCG is itself a tumor marker — elevated serum hCG is a diagnostic criterion for gestational trophoblastic disease (choriocarcinoma), germ cell tumors of the ovary and testis, and some non-trophoblastic malignancies. Any man or non-pregnant woman with unexpectedly elevated serum hCG should be evaluated for these malignancies before hCG supplementation begins. Second, LHCGR is expressed on several tumor types including thyroid carcinoma, breast carcinoma, prostate carcinoma, and adrenal tumors — the concern that exogenous hCG could stimulate tumor growth via LHCGR activation in these contexts is theoretically grounded. Active malignancy of any type: contraindication pending oncologist evaluation. History of androgen-responsive prostate cancer: specific contraindication (testosterone stimulation). History of estrogen-responsive breast cancer: specific concern (aromatization increases estrogen).

Ovarian hyperstimulation syndrome (OHSS): a potentially life-threatening complication of ovarian stimulation in women undergoing fertility treatment. hCG-triggered ovulation in women with ovarian hyperstimulation produces excess VEGF from stimulated follicles → capillary leak syndrome → ascites, pleural effusion, hemoconcentration, thrombosis. OHSS ranges from mild (bloating, nausea) to severe (hospitalization required). This complication is specific to the fertility application in women undergoing controlled ovarian stimulation — it is not relevant to the male PCT or TRT adjunct context.

Post-cycle therapy with hCG typically occurs during a period of significant hormonal flux: the transition from supraphysiological androgen levels during the AAS cycle to the crash of testosterone immediately post-cycle, then the gradual recovery through PCT. hCG's role in PCT is to prevent the worst of this testosterone crash by maintaining Leydig cell output. Mood effects: during the hCG phase of PCT, testosterone levels are partially maintained; most users report this as psychologically more stable than a cold-turkey transition to PCT without hCG. Post-PCT crash is less severe when hCG has been used. Libido: hCG maintains testosterone-dependent libido during PCT more effectively than SERM-only protocols. Estrogen monitoring is important — excessive estrogen from hCG-stimulated aromatization can impair mood and libido independently of testosterone levels.

hCG is supplied as lyophilized powder in vials of 1,000-10,000 IU. Reconstitute with bacteriostatic water. For TRT/PCT use, common concentrations: 2,000 IU/mL (from a 5,000 IU vial reconstituted in 2.5 mL). Store lyophilized powder at room temperature or refrigerated (below 25°C). Reconstituted solution: refrigerate at 2-8°C; use within 60 days. hCG is notably stable compared to most peptides — bacteriostatic water reconstituted hCG is stable for up to 60 days refrigerated, which is longer than most GH secretagogues or healing peptides.

This is the most dangerous PCT misconception. Using hCG as PCT monotherapy raises testosterone (via Leydig cell stimulation) but simultaneously suppresses pituitary LH production via negative feedback from that elevated testosterone. The HPG axis does not recover during hCG-only PCT — it remains suppressed by hCG's hormonal output. When hCG stops, testosterone crashes again with a pituitary that still hasn't been given a chance to recover. SERMs (clomiphene or tamoxifen) are required in Phase 2 to unblock the pituitary's estrogen-receptor-mediated LH suppression and allow spontaneous LH recovery. PCT without SERMs typically results in delayed or incomplete testosterone recovery.

Some community protocols (borrowed from older literature) recommend concurrent hCG + SERM for the entirety of PCT. This is pharmacologically counterproductive: hCG raises testosterone → testosterone suppresses LH (the same feedback the SERM is trying to overcome) → SERMs cannot fully restore LH pulsatility while hCG is maintaining high testosterone. The sequential approach — hCG phase then SERM phase, with a washout in between — gives each agent its optimal pharmacological window.

This has been addressed fully in Section 6. hCG has no effect on weight loss beyond caloric restriction. The 500-calorie diet produces weight loss; hCG does not contribute to it. The FDA's prescribing label says exactly this. Fourteen RCTs confirm it. Physicians who prescribe hCG for weight loss off-label are prescribing a compound that its own FDA-approved label describes as not effective for that use.

Homeopathic hCG contains no hCG molecules — the dilution process eliminates any actual compound. Even if they did contain hCG, oral administration would degrade it in the GI tract before absorption. OTC 'hCG' products are pharmacologically inert for any intended purpose. They are illegal to sell for weight loss purposes per FDA and FTC guidance.

hCG maintains testicular function by substituting for LH — it does not address the reason LH is suppressed (pituitary negative feedback from exogenous androgens). Once hCG stops, if the pituitary has not been given a chance to recover normal GnRH/LH pulsatility (which requires SERM therapy), testosterone will crash again. hCG is a bridge, not a cure. The path to fully restored natural testosterone production requires both testicular reactivation (hCG phase) and pituitary axis recovery (SERM phase).

Pregnyl (Organon): urinary-derived hCG; 5,000 IU/mL and 10,000 IU/mL; FDA-approved; requires prescription. Novarel (Ferring Pharmaceuticals): urinary-derived hCG; 5,000 IU/mL and 10,000 IU/mL; FDA-approved; requires prescription. Ovidrel (EMD Serono): recombinant hCG (choriogonadotropin alfa, r-hCG); 250 mcg/0.5 mL prefilled syringe; FDA-approved specifically for ART (assisted reproductive technology); more precise dosing than urinary-derived products. Urinary vs recombinant: urinary hCG (Pregnyl, Novarel) is purified from the urine of pregnant women; recombinant hCG (Ovidrel) is produced by CHO cell expression; both activate LHCGR equivalently; recombinant is more consistent in potency but more expensive.

Physicians may prescribe FDA-approved hCG injection (Pregnyl, Novarel) off-label for male hypogonadism management, TRT adjunct, and PCT support — this is legal medical practice. Compounding pharmacies may prepare hCG formulations not available as commercial products (different concentrations, combination preparations). The FDA's 2023-2024 compounding restrictions that targeted many peptides did not categorically restrict compounding of hCG in the same way — hCG's FDA-approved status creates a different regulatory pathway from unapproved research chemicals. Telemedicine prescribing of hCG for TRT adjunct and fertility has expanded substantially since 2020.

Given hCG's central role in PCT protocols, it is widely available through gray-market peptide vendors and black-market sources. Quality concerns: pharmaceutical-grade hCG (Pregnyl, Novarel) from a pharmacy is reliably dosed and sterile. Gray-market hCG: potency claims are unverified; HPLC can confirm the presence of protein but may not verify hCG-specific activity or IU potency. Counterfeit products: some products contain diluted, underdosed, or misdosed hormone. The stakes for incorrect dosing in PCT are meaningful — an underdosed hCG phase leaves Leydig cells insufficiently primed, prolonging testosterone recovery.

An emerging question in PCT pharmacology is whether newer gonadotropin-related agents could replace or supplement hCG. Recombinant human LH (lutropin alfa, Luveris) has a half-life of approximately 10 hours — longer than endogenous LH (30 minutes) but shorter than hCG (36 hours); it requires more frequent dosing and is more expensive; not a significant improvement over hCG for Leydig cell stimulation purposes. Kisspeptin-10 is a neuropeptide that directly stimulates hypothalamic GnRH pulse neurons — it works upstream of the pituitary, potentially offering a more physiological approach to HPG axis restoration. Small human trials show kisspeptin-10 reliably stimulates LH pulses. Whether kisspeptin-10 represents a superior PCT option to the sequential hCG-then-SERM protocol is an open question; the evidence base for kisspeptin in PCT is preliminary (Grade D-E) and no comparative trial against the standard hCG-SERM protocol has been completed. The standard hCG-then-SERM sequential protocol remains the most evidence-supported PCT approach as of 2026.

Lee JA, Ramasamy R. (2018). Indications for the use of human chorionic gonadotropic hormone for the management of infertility in hypogonadal men. Translational Andrology and Urology. 7(Suppl 3):S348-S352. PMC6087849. [Review of hCG's role in preserving fertility during testosterone therapy and treating HH; mechanism, evidence, and protocols.]

FDA Prescribing Information. Pregnyl (choriogonadotropin alfa for injection). Organon. [FDA-approved label containing the explicit statement: 'There is no substantial evidence that it increases weight loss beyond that resulting from caloric restriction.']

Greenway FL, Bray GA. (1977) [2]. Human chorionic gonadotropin (HCG) in the treatment of obesity: a critical assessment of the Simeons method. Western Journal of Medicine. 127(6):461-463. [Early systematic review; no benefit of hCG for weight loss.]

Lijesen GK, Theeuwen I, Assendelft WJ, Van Der Wal G. (1995) [3]. The effect of human chorionic gonadotropin (HCG) in the treatment of obesity by means of the Simeons therapy. Journal of Clinical Endocrinology and Metabolism. 80(9):2766-2769. [Meta-analysis of 14 RCTs: no benefit of hCG over placebo for weight loss in calorie-restricted subjects.]

FDA Consumer Update: HCG Diet Products Are Illegal. (2011, updated 2013). FDA.gov. [FDA/FTC warning letters; FDA's official position on hCG and weight loss; statement that OTC hCG products are illegal.]

Coviello AD, Bremner WJ, Matsumoto AM et al. (2004) [4]. Intratesticular testosterone concentrations comparable with serum levels are not sufficient to maintain normal sperm production in men gonadotropin-suppressed with a GnRH antagonist. Journal of Andrology. 25(6):931-938. [Establishes that ITT must be maintained at high concentrations for spermatogenesis; supports the ITT concept central to hCG's fertility-preservation mechanism.]

Jhaveri K, Shreeram A, Bajaj A et al. (2024) [5]. Fertility and Testosterone Injections — How to Preserve Spermatogenesis in Men. Clinical Guidance update. [2024/2025 clinical guidance on preserving fertility during TRT; HCG co-therapy protocols; sperm count preservation evidence.]

• TRT adjunct for fertility preservation: 250-500 IU SubQ 2-3x/week concurrent with testosterone therapy. Physician-supervised. Monitor estradiol. This is the most well-evidenced use in the community context.
• PCT Phase 1 (testicular priming): 1,000-2,500 IU EOD for 10-14 days immediately post-cycle. Stop 3 days before Phase 2 (SERM). Sequential, not concurrent.
• On-cycle prophylaxis: 250 IU 2x/week throughout cycle prevents atrophy and simplifies PCT.
• Weight loss: hCG does not work for weight loss. Not a valid application.
• Athletes in tested sports: WADA S2 banned at all times; absolute prohibition; mandatory TUE for any legitimate medical use.

— End of Human Chorionic Gonadotropin —

THE PEPTIDE BIBLE | Human Chorionic Gonadotropin | For Research & Educational Purposes Only