HCG (human chorionic gonadotropin)

HCG (human chorionic gonadotropin) is a hormone produced during pregnancy that has luteinizing hormone (LH)–like activity. Purified and recombinant forms of HCG are used in regulated reproductive and endocrine medicine.

Beyond those indications, HCG is sometimes referenced in weight-loss or performance discussions, often in ways that diverge from evidence-based practice and local regulations.

Therapeutic HCG binds to LH receptors in the gonads, leading to:

• Stimulation of sex-steroid production (e.g., estrogen and progesterone in the ovary)
• Support of ovulation or corpus luteum function in fertility protocols
• In certain endocrine contexts, support of testosterone production in males by acting on Leydig cells

These effects underpin both established reproductive uses and some of the off-label or experimental contexts in which HCG is discussed.

In regulated medicine, HCG may be used:

• As part of assisted reproductive protocols to trigger ovulation or support luteal function
• In selected endocrine conditions to stimulate endogenous testosterone production in males under specialist care

Exact indications, combinations, and dosing strategies are defined by product labeling and specialist guidelines. Uses of HCG in weight-loss regimens or unsupervised hormone manipulation are controversial and often not aligned with regulatory or evidence-based standards.

HCG appears on the WADA Prohibited List as the first bullet of sub-section S2.2.1, "Testosterone-stimulating peptides in males," alongside luteinizing hormone (LH), "gonadotrophin-releasing hormone (GnRH, gonadorelin) and its agonist analogues," and kisspeptin and its agonist analogues. It is a non-Specified Substance, so the default first-violation sanction is four years.

The sex-specific condition, stated precisely. The restriction is scoped by the sub-section heading itself: these are testosterone-stimulating peptides in males. HCG is prohibited for male athletes at all times, in and out of competition. It is not prohibited for female athletes, because in women it does not produce the testosterone rise the category exists to prevent — which is also why a pregnancy test result is not an anti-doping finding. Athletes should confirm the current scope against the List for their testing year rather than relying on a remembered rule; this is a sub-section WADA has already rewritten once, for the 2024 List.

Why hCG is prohibited in men. Doping analysts describe the rationale without euphemism. "Human chorionic gonadotropin (hCG) stimulates testosterone production by the testicles and can normalize suppressed testosterone concentrations in males following prolonged anabolic steroid use. Because of the potential for abuse by males, hCG is on the World Anti-Doping Agency (WADA) list of prohibited substances" (Butch et al., Drug Test Anal 2018). That is the exact use case most often described in gray-market discussion — restarting the axis during or after a steroid cycle — and it is the use the prohibition is aimed at.

Testing is threshold-based, and the threshold is under active revision. HCG is one of the few prohibited peptides measured against a numeric decision limit rather than simply detected. Historically, "urinary concentrations of hCG > 5 IU/L may be an indicator of doping," with initial testing and confirmation performed on two different immunoassay platforms (Kuuranne et al., Drug Test Anal 2013). Only assays recognising the intact alpha–beta heterodimer are used, "since intact hCG is the only biologically active molecule," and WADA requires confirmation on a different intact-hCG immunoassay from the one used in screening, or by LC-MS/MS (Butch 2018).

Butch's group measured 570 male urine samples by immunoextraction LC-MS/MS and found a mean intact hCG concentration of 0.04 IU/L with a 97.5th-percentile upper reference limit of 0.21 IU/L — far below the historical cut-off. On that basis they recommended "a threshold of 1.0 IU/L for intact hCG (false positive rate of <1 in 10 000) for detecting male athletes that dope with hCG." The practical implication for an athlete is the opposite of reassuring: as reference data improve, thresholds move down, not up.

A named sanction shows the enforcement route in practice. Vahe Aivazian, a masters cyclist, accepted a four-year USADA sanction beginning 7 April 2021 for possessing and using ten prohibited substances including human chorionic gonadotropin (hCG), alongside testosterone, nandrolone, somatropin, ipamorelin, CJC-1295, GHRP-6, DHEA and anastrozole (USADA sanction announcement). The violation rested on possession and use rather than on a urinary threshold being exceeded — a reminder that the decision limit governs one route to a finding, not the only one.

Because hCG has genuine approved indications in male endocrine and fertility medicine, a male athlete with a documented clinical need pursues a therapeutic use exemption in advance, through his anti-doping organization. A prescription on its own is not an exemption.

Reported risks include ovarian hyperstimulation syndrome (OHSS) and multiple pregnancy in fertility settings, as well as injection-site reactions, mood changes, and various hormone-related symptoms. In males, endocrine testing and careful monitoring are important when HCG is used for hypogonadal conditions.

Because effects depend strongly on context and co-therapies, safety assessment should always be individualized and clinician-led.

HCG mimics LH and is used to stimulate testicular or ovarian function. Protocols differ vastly between fertility, hypogonadism, and diet contexts.

Note: HCG raises testosterone levels in men but suppresses natural LH/FSH production via negative feedback if used for long periods without breaks.

HCG is supplied as a lyophilized powder packaged with a separate bacteriostatic solvent, so the strength in the syringe is determined by how much diluent is added rather than fixed by the vial. Products differ by source: older preparations are purified from the urine of pregnant women, while recombinant choriogonadotropin alfa is produced in cell culture. The label for urinary-derived product carries a specific anaphylaxis warning that recombinant material does not share (Pregnyl, DailyMed).

In fertility care HCG is almost never used alone. It follows a course of FSH-containing gonadotropins that grow the follicles, and supplies only the terminal LH-like surge; the label reflects this by defining the ovulation-induction dose relative to the last dose of those gonadotropins. In male hypogonadism the same logic applies in reverse — pooled data across 41 studies and 1,673 patients found combined hCG plus FSH outperformed hCG alone on every sperm-concentration threshold measured, despite similar effects on testosterone and testicular volume (PMID 39445789). hCG restores one arm of the gonadotropin signal, not both.

HCG has been studied extensively as part of assisted reproductive technologies and in selected endocrine conditions. Outcomes include ovulation and pregnancy rates, sex-steroid levels, and safety endpoints such as OHSS.

In contrast, evidence for HCG-based weight-loss approaches or other non-standard uses is limited and often does not support strong claims. Interpretation of HCG research therefore depends heavily on the clinical question being asked.

For deeper dives on this peptide, see:

• HCG (human chorionic gonadotropin) benefits and areas of interest
• HCG (human chorionic gonadotropin) side effects and safety context
• HCG (human chorionic gonadotropin) dosing concepts (educational)
• HCG (human chorionic gonadotropin) research and evidence overview

What is HCG approved for? Three things. The Pregnyl label lists prepubertal cryptorchidism not due to anatomical obstruction, selected cases of hypogonadotropic hypogonadism in males, and induction of ovulation and pregnancy in anovulatory infertile women whose anovulation is not due to primary ovarian failure and who have already been treated with gonadotropins (DailyMed).

Does the "HCG diet" work? No, and this is one of the few questions in peptide medicine with a settled answer. A criteria-based meta-analysis of 8 controlled and 16 uncontrolled trials found that of the 12 studies scoring 50 or more on a 100-point quality scale — all controlled — exactly one reported HCG as a useful adjunct, and concluded there is no scientific evidence it produces weight loss, fat redistribution, reduced hunger, or improved well-being (PMID 8527285). The FDA-approved label says the same thing in capital letters: "HCG HAS NO KNOWN EFFECT ON FAT MOBILIZATION, APPETITE OR SENSE OF HUNGER, OR BODY FAT DISTRIBUTION."

Why is HCG used alongside testosterone therapy? Exogenous testosterone suppresses pituitary LH, which collapses intratesticular testosterone — the local concentration spermatogenesis depends on, not the serum level. Literature on testosterone-associated infertility describes hCG, including low-dose hCG given with testosterone, among the strategies used to protect the testis, and notes that most men recover sperm production within a year of stopping testosterone anyway (PMID 26813847). This use is off-label.

How well does it restore fertility in men? Partially. Across 41 studies and 1,673 men with pathological gonadotropin deficiency, mean sperm concentration after a median 18 months was 11.6 M/mL; 78% produced any sperm but only 15% exceeded 20 M/mL. Combined hCG plus FSH outperformed hCG alone throughout (PMID 39445789).

What is the main safety concern? In ovarian stimulation it is ovarian hyperstimulation syndrome, which the label describes as a distinct medical event driven by a dramatic increase in vascular permeability and capable of progressing rapidly — with ascites, pleural effusion, acute pulmonary distress, and thromboembolic reactions in severe cases. Details are on the side-effects page.