HCG

Summary

HCG is a hormone the placenta produces during pregnancy, and its FDA label describes it as a polypeptide made of an alpha and a beta subunit — the alpha subunit is essentially identical to the one in luteinizing hormone (LH). That similarity is the whole story. HCG acts on the same receptor as LH, which is why an injection tells the testes to make testosterone or tells a mature ovarian follicle to release an egg.

It is a genuinely old, genuinely approved prescription drug, which makes it unusual on this site: most of what we cover is either investigational or unapproved. HCG is neither. It is also the compound with the most direct evidence against its most famous use. Its own FDA label states, in capital letters, that HCG has not been shown to work for obesity and has no known effect on fat mobilisation, appetite, or body fat distribution. That sentence has been on the label for decades, and the HCG diet has been sold underneath it the whole time.

What people use it for

Three very different populations use HCG, and they rarely talk to each other.

Fertility patients get it as the ovulation trigger — the injection timed to a monitored cycle that releases the egg. This is the approved use, and it happens under supervision in fertility clinics worldwide.

Men on testosterone replacement use it off-label to keep the testes working. Exogenous testosterone shuts down the body's own LH signal, testicular testosterone collapses, and sperm production fails; HCG substitutes for the missing LH. This is the use that drives most peptide-forum interest in HCG, along with its cousin use in "post-cycle therapy" after anabolic steroids. A smaller group uses HCG instead of testosterone therapy, hoping to raise testosterone without shutting the system down.

Dieters buy it for the HCG diet — the Simeons protocol, which pairs HCG with a roughly 500-calorie-a-day diet. This is by far the largest group by volume and the one with no supporting evidence at all.

Human evidence

Ovulation induction — the approved use. Both the urinary-derived product and the recombinant version (choriogonadotropin alfa, Ovidrel) are FDA-approved to trigger final follicular maturation and ovulation, and HCG has been standard practice in assisted reproduction for decades. This is settled clinical medicine rather than an open research question, which is what S+ describes: approved products, established labelling, and consensus use. Note what it is not — it is not a fertility treatment on its own, and both labels place it at a specific point in a monitored, pretreated cycle.

Preserving testicular function during testosterone therapy. This has the most interesting evidence on the page. A 2005 randomized trial at the University of Washington gave 29 men 200 mg testosterone enanthate weekly — enough to suppress LH and FSH to 5% and 3% of baseline — plus saline placebo or 125, 250 or 500 IU of HCG every other day for three weeks, and measured testosterone inside the testis by needle aspiration. On testosterone alone, intratesticular testosterone fell by 94%. With HCG it rose in a straight line with dose: 25% below baseline at 125 IU, 7% below at 250 IU, and 26% above baseline at 500 IU.

That is a clean dose-response experiment on the exact mechanism. What it does not do is measure sperm counts or pregnancies, and the authors said so — the study was designed to find the minimum dose, not to prove fertility is preserved. The nearest evidence on that endpoint is a 2013 retrospective review of 26 hypogonadal men taking testosterone with 500 IU of HCG every other day: no man became azoospermic, semen parameters did not deteriorate over more than a year of follow-up, and nine of the 26 contributed to a pregnancy. A chart review with no control group cannot rule out that these men would have done fine anyway, and 40% azoospermia on testosterone alone is the comparison it is implicitly making rather than one it measured.

One small randomized trial of a surrogate endpoint plus one uncontrolled series is real human evidence and clearly limited — which is exactly what S means here.

HCG as a standalone testosterone raiser. A 2019 multi-institution case series followed 20 men with hypogonadal symptoms but testosterone already above 300 ng/dL who were given HCG on its own. Mean testosterone rose 49.9%, from 362 to 520 ng/dL, and half reported symptom improvement. Twenty men, no control group, no blinding, and a symptom endpoint on which half the group not improving is as notable as half improving. Testosterone going up is expected pharmacology; whether men feel better because of the drug is not something an uncontrolled series can answer, which is why this grades B.

Obesity — the claim that fails. A 1995 criteria-based meta-analysis traced 24 trials of HCG for obesity (eight controlled, sixteen uncontrolled), scored each for methodological quality out of 100, and found scores from 16 to 73 — most studies were poor. Of the twelve that scored 50 or above, one reported HCG was a useful adjunct. The authors concluded there is no scientific evidence HCG is effective in treating obesity: it does not produce weight loss or fat redistribution, and it does not reduce hunger or improve well-being.

The FDA reached the same conclusion and put it on the label in capitals. As the agency's consumer guidance puts it, weight loss on the HCG diet comes from severe calorie restriction, not from the HCG — which is the only thing anyone loses weight on when eating 500 calories a day. That is a C: not merely unproven, but tested and contradicted.

Cryptorchidism — approved, and not supported. This one is uncomfortable, because it is an FDA-approved indication. A 2018 meta-analysis pooled seven randomized controlled trials and rated their overall quality low. HCG was no more effective than placebo for testicular descent, and no different from GnRH. The placebo comparison rested on two tiny trials totalling 31 boys, so this is better read as "no trial has ever shown it works" than as proof it does nothing. Either way, the American Urological Association's guideline states plainly that hormonal therapy is not recommended and that orchidopexy — surgery — is the successful therapy. An approval granted under an older evidentiary standard is not the same as evidence, and here the two disagree. C.

Animal / preclinical evidence

Unusually for this site, the preclinical work is not the interesting part. HCG's mechanism was established long ago and is described in the drug's own label: it acts on the LH receptor, stimulating testosterone production by the testicular Leydig cells, and substituting for the mid-cycle LH surge that triggers ovulation in women. The label also notes that HCG-induced testicular descent in cryptorchidism is usually reversible once the drug is stopped — a mechanistic detail that fits the trial results above.

Everything worth grading about HCG has been tested in people, which is why the grades rest entirely on human data.

Anecdotal / community reports

Low-confidence. These are community reports, not evidence. Not medical guidance.

Two community narratives dominate, and both overreach in the same direction.

In men's-health and bodybuilding forums, HCG is discussed as the thing that stops testicular atrophy on testosterone or restarts the system afterwards. The atrophy part matches the pharmacology and the Coviello data; the "restart" part — post-cycle protocols promising a return to baseline function — is not something any of the studies above tested. Detailed protocols circulate that specify doses, timings and taper schedules with a confidence no published trial supports.

In dieting communities, the HCG diet persists despite the label, the meta-analysis, and a federal enforcement action. It persists for an obvious reason: people on it lose weight fast, because they are eating 500 calories a day. The experience is real and the attribution is wrong, and that is a hard thing to argue against with a chart.

Doses used in published studies

Context only — not a recommendation. PeptideIQ Base does not provide dosing advice.

HCG is one of the few compounds on this site where the doses come from an FDA label rather than reconstructed trial data, so the table above is unusually solid. Note first what the label says about route: Intramuscular Use Only — the subcutaneous administration common in off-label practice is not what the approved labelling describes.

For hypogonadotropic hypogonadism in males, the label lists two regimens: 500–1,000 units three times weekly for three weeks then twice weekly for three more, or 4,000 units three times weekly for six to nine months, optionally stepping down to 2,000 units three times weekly. For ovulation induction, a single dose of 5,000–10,000 units one day after the last menotropins dose; recombinant Ovidrel uses 250 mcg subcutaneously in the same position in the cycle. The cryptorchidism regimens are listed in the table for completeness, alongside the grade explaining why the evidence does not support them.

The off-label TRT-adjunct doses come from research rather than a label: 125, 250 or 500 IU every other day in the 2005 randomized trial, and 500 IU every other day in the 2013 retrospective series. These are published figures, which is why they appear here rather than in a community-practice block — but a published figure is not a protocol, and every one of these was given under medical supervision with monitoring.

There is no dose of HCG for weight loss, because there is no approved or evidenced use for weight loss. Any figure presented as one has no source behind it.

Safety & side effects

Contraindications on the label are precocious puberty, prostate carcinoma or other androgen-dependent tumour, and prior allergic reaction to HCG.

Listed adverse reactions are headache, irritability, restlessness, depression, fatigue, edema, precocious puberty, gynecomastia, and injection-site pain. Gynecomastia is the one most relevant to men using HCG off-label: stimulating testicular testosterone also increases the substrate available for conversion to estradiol.

The serious reactions in the label attach mainly to fertility use in combination with menotropins: ovarian hyperstimulation syndrome — which can involve ovarian enlargement, ascites and pleural effusion — rupture of ovarian cysts with bleeding into the abdomen, multiple births, and arterial thromboembolism. Anaphylaxis and other hypersensitivity reactions have been reported with urinary-derived HCG products. The label warns that HCG should be used with menotropins only by physicians experienced in infertility. In boys treated for cryptorchidism, HCG's androgen stimulation can induce precocious puberty, and the label directs that treatment stop if signs appear. Because androgens cause fluid retention, the label advises caution in cardiac or renal disease, epilepsy, migraine and asthma.

On weight-loss use specifically, the FDA states it has received reports of serious adverse events associated with HCG injections used for weight loss, including pulmonary embolism, depression, cerebrovascular events, cardiac arrest and death. Separately, the 500-calorie diet the protocol requires carries its own risks — gallstone formation, electrolyte imbalance and irregular heartbeat — and the agency notes such diets should only be undertaken with medical supervision.

Regulatory / legal status

HCG is FDA-approved, prescription-only, and injectable, for three indications on the urinary-derived label — prepubertal cryptorchidism not due to anatomical obstruction, selected cases of hypogonadotropic hypogonadism in males, and ovulation induction in anovulatory infertile women pretreated with menotropins — plus the recombinant Ovidrel's approval for triggering final follicular maturation in assisted reproduction.

It is not approved for weight loss, and the FDA is explicit that no oral, sublingual or "homeopathic" HCG product is approved for any purpose: all such products are illegally marketed. In 2011 the FDA and FTC acted jointly against marketers of over-the-counter "homeopathic" HCG weight-loss drops, and the agency's guidance still names the products involved.

Use alongside testosterone replacement to preserve testicular function is off-label. Off-label prescribing is legal and routine, and it is also, as the FDA notes, the situation in which the least is known about risks and benefits — which is a fair description of the evidence base above.

In sport, chorionic gonadotrophin appears on the WADA Prohibited List under S2.2.1, testosterone-stimulating peptides in males, alongside LH, GnRH analogues and kisspeptin. Everything in class S2 is prohibited at all times, in and out of competition, and is a non-Specified Substance. The prohibition applies to male athletes. Status can change and varies by country; this is not legal or medical advice.

Podcast / media mentions

HCG gets discussed in two separate conversations that almost never acknowledge each other.

In men's-health and fitness media it appears as the sophisticated addition to testosterone therapy — the thing that separates people who know what they are doing from people who do not. There is a real basis for that: the mechanism is established and the intratesticular-testosterone data is good. What the confident version usually skips is that the strongest study is a three-week experiment in 29 men measuring a hormone level, not a fertility outcome, and that the fertility evidence is a chart review of 26 patients.

In diet and wellness media it appears as the HCG diet, still, decades after its own label said it does not work and thirty years after a meta-analysis of 24 trials reached the same conclusion. The critique here is not of the people who tried it — losing weight on 500 calories a day is not an illusion. It is of anyone still selling the hormone as the reason it happened, when the label they are selling underneath says otherwise in capital letters.