Hormonal
HCG
Prepared by the ezGLP team. Sources last checked . Profile reviewed .
Also known as Human Chorionic Gonadotropin
Routes represented in the knowledgebase: Subcutaneous (SubQ).
Educational overview
HCG is listed in the ezGLP knowledgebase under Hormonal. Evidence and regulatory status can vary by formulation, route, and jurisdiction.
Human chorionic gonadotropin (hCG) is a glycoprotein hormone produced by the placenta during pregnancy. It is a heterodimer whose beta subunit closely resembles luteinizing hormone (LH), and it acts on the LH/hCG receptor in the gonads: in the ovary it triggers final follicular maturation and ovulation and supports the corpus luteum, and in the testis it stimulates Leydig cells to produce testosterone. Pharmaceutical hCG is either purified from the urine of pregnant women (products such as Pregnyl and Novarel) or made by recombinant DNA technology as choriogonadotropin alfa (Ovidrel). It is a hormone rather than a peptide secretagogue, and it is dosed in international units of biological activity.
hCG has decades of clinical trial evidence in reproductive medicine, where it is a standard agent for triggering ovulation in assisted reproduction, for treating hypogonadotropic hypogonadism in men, and for prepubertal cryptorchidism. Coviello and colleagues showed in 2005 that low doses maintained intratesticular testosterone in men whose own LH was suppressed by exogenous testosterone, which underpins its use to preserve fertility during androgen therapy. Pharmacokinetic studies such as Saal and colleagues' 1991 comparison of subcutaneous and intramuscular injection report a terminal half-life of roughly one to two days. By contrast, Lijesen and colleagues' 1995 meta-analysis found no scientific evidence that hCG contributes to weight loss beyond calorie restriction.
hCG is FDA-approved as a prescription injectable for ovulation induction, for hypogonadotropic hypogonadism in males, and for prepubertal cryptorchidism, with labelled warnings covering ovarian hyperstimulation syndrome, thromboembolism, and fluid retention. The FDA states explicitly that no hCG product is approved for weight loss, that there is no substantial evidence it increases weight loss beyond that from severe calorie restriction, and that homeopathic or over-the-counter hCG diet products are unapproved and illegal. Products with the same indications are authorised in the European Union, the United Kingdom, Canada, and Australia. The World Anti-Doping Agency prohibits hCG in male athletes only, under section S2.1, as a stimulator of endogenous testosterone.
Urinary hCG is supplied as a lyophilised powder in a vial, usually packaged with a diluent, and is reconstituted with bacteriostatic or sterile water before subcutaneous or intramuscular injection; the recombinant product is a ready-to-use prefilled syringe. Labels for the urinary products call for refrigeration after reconstitution and discard within a specified number of days, while unopened vials are typically kept at controlled room temperature, so the dispensing label governs handling. Because the product is measured in international units rather than milligrams, an inventory record for hCG usually captures the units per vial, the diluent volume added, the resulting units per millilitre, the reconstitution date, and the lot number.
- Category
- Hormonal
- Routes represented
- Subcutaneous (SubQ)
- Approximate library half-life
- 33 hours; formulation-dependent and not dosing guidance
- Storage context
- Follow the dispensed product or pharmacy label; storage and beyond-use time vary by formulation.
Published literature
Safety evidence
Common or reported: headache, irritability, fatigue, edema, injection-site reactions, gynecomastia.
Serious or important: anaphylaxis, ovarian hyperstimulation syndrome, ovarian cyst complications, thromboembolism, fluid retention.
Safety evidence sourceCommon questions
Is hCG FDA approved?
Yes, for specific indications. Prescription hCG products such as Pregnyl and Novarel are FDA-approved for inducing ovulation in anovulatory women, for treating hypogonadotropic hypogonadism in males, and for prepubertal cryptorchidism not due to anatomical obstruction. The recombinant form, choriogonadotropin alfa, is approved for ovulation triggering in assisted reproduction. The FDA has never approved any hCG product, prescription or over-the-counter, for weight loss or any other use outside these labelled indications.
Does hCG help with weight loss?
The evidence says no. Lijesen and colleagues' 1995 meta-analysis of controlled trials found no scientific support for hCG as an adjunct to weight loss, and the FDA states that hCG has not been demonstrated to be effective in treating obesity and that any loss on hCG diet programs comes from the accompanying very-low-calorie diet. The FDA also warns that homeopathic hCG drops, pellets, and sprays sold for weight loss are unapproved and illegal.
What does hCG do for men on testosterone?
Because hCG acts like luteinizing hormone on Leydig cells, it can keep the testes producing testosterone when the pituitary's own LH output is suppressed. Coviello and colleagues demonstrated in 2005 that low-dose hCG maintained intratesticular testosterone in normal men given exogenous testosterone. Clinicians rely on this property to preserve testicular volume and spermatogenesis during androgen therapy, although that use falls outside the FDA-labelled indication of hypogonadotropic hypogonadism.
Is hCG banned in sport?
For male athletes, yes. The World Anti-Doping Agency Prohibited List includes chorionic gonadotrophin (CG) and luteinizing hormone under section S2.1 as prohibited in males only, because they stimulate endogenous testosterone production. The prohibition applies at all times, in and out of competition. hCG is not prohibited for female athletes, where its use is confined to fertility treatment and it produces no performance-relevant androgen increase.
How is hCG stored after mixing?
Storage depends on the product. The FDA labels for urinary hCG products such as Pregnyl direct that the lyophilised powder be kept at controlled room temperature before reconstitution and that the reconstituted solution be refrigerated and discarded after a labelled number of days, which differs between brands. The recombinant prefilled syringe is stored refrigerated. Compounded hCG follows the dispensing pharmacy's beyond-use date rather than a manufacturer label.
Further reading
- DailyMed, Pregnyl (chorionic gonadotropin for injection) prescribing information
- FDA, Questions and answers on HCG products for weight loss
- Betz & Fane, StatPearls (NCBI Bookshelf): Human chorionic gonadotropin
- Coviello et al., J Clin Endocrinol Metab 2005 (low-dose hCG maintains intratesticular testosterone)
- Saal et al., Fertil Steril 1991 (pharmacokinetics after subcutaneous and intramuscular hCG)
- Lijesen et al., Br J Clin Pharmacol 1995 (meta-analysis of hCG in the treatment of obesity)
- World Anti-Doping Agency, The Prohibited List (section S2.1)
Summarised from published literature for reference only, with citations to the source. Evidence is graded as reported and is not a recommendation to combine, dose, or use any compound.
For personal tracking and education only. Not medical advice, diagnosis, or treatment, and not a medical device. Peptides may be prescription-only or unapproved where you live. Consult a licensed healthcare professional.