What it is
Human chorionic gonadotropin, or hCG, is the hormone that pregnancy tests look for. The placenta makes it early in pregnancy. It keeps the ovary making the hormones that support the pregnancy. It works on the same target (receptor) as LH. LH is a hormone from the pituitary gland in the brain. In women, LH triggers the release of an egg. In men, it tells the testes to make testosterone.
This shared action explains its approved medical uses. In the United States, it is approved for three things. It can trigger the release of an egg in fertility treatment. It can push the testes to work in men whose pituitary does not make enough LH. It can help undescended testicles move down in young boys.
Most substances on this site are short chains of amino acids (peptides). hCG is different. It is a large protein with sugar chains attached. The labels for hCG made from urine say it has not been shown to work for weight loss.
hCG is a heterodimeric glycoprotein of a 92-residue α subunit, common in structure to LH and FSH, and a 145-residue β subunit that confers specificity; both carry N- and O-linked glycans, and a C-terminal extension of the β subunit is reported to prolong its circulation relative to LH. It is a full agonist at the LH/choriogonadotropin receptor (LHCGR), a Gs-coupled receptor on ovarian theca and granulosa-lutein cells and testicular Leydig cells. Activation raises cAMP and drives steroidogenesis; in the pre-ovulatory follicle it induces final oocyte maturation, resumption of meiosis and follicular rupture, and in men it stimulates testosterone production and, indirectly, spermatogenesis.
Pharmacokinetics (Ovidrel label, recombinant hCG 250 µg subcutaneously): peak concentration at 12–24 hours, bioavailability about 40% and a terminal half-life of about 29 hours. Urinary products are dosed in USP units, recombinant product in micrograms; 250 µg recombinant hCG was judged equivalent to 10,000 units of urinary hCG in the trial that supported Ovidrel.
Who made it and when
In 1927, two doctors in Berlin made a discovery. Selmar Aschheim and Bernhard Zondek found that urine from pregnant women made young female mice come into heat. This became the first reliable pregnancy test. The substance behind it was later found to be hCG, a hormone made by the placenta.
For many years, the medicine was taken from the urine of pregnant women and purified. In the United States, Ferring’s Novarel dates from 1974. Organon’s Pregnyl dates from 1976. Generic versions also exist. A lab-made (recombinant) version was approved in 2000. It is called Ovidrel, from EMD Serono. It is made in hamster cells grown in a lab. In March 2020, US law moved all these products into the class of biological products.
Aschheim and Zondek described the gonadotropic activity of pregnancy urine in 1927, the basis of the A-Z bioassay; they attributed it to the pituitary, and later work showed it came from the placenta. Urinary hCG was developed into injectable products; FDA’s deemed-BLA list gives initial NDA approval dates of 1974-01-15 for Novarel (NDA 017016, Ferring) and 1976-10-20 for Pregnyl (NDA 017692, Organon), alongside other urinary products from Fresenius Kabi and others. Ovidrel (choriogonadotropin alfa, NDA 021149, EMD Serono) followed on 2000-09-20.
A transition provision of the Biologics Price Competition and Innovation Act of 2009 provided that on 2020-03-23 approved applications for biological products under section 505 of the FD&C Act would be deemed licences under section 351 of the PHS Act. All hCG and choriogonadotropin alfa applications appear on FDA’s transition list, which gives their former NDA numbers; the current Pregnyl label carries a US biologics licence number. No current compound patent applies to urinary hCG.
What the data say
For its approved fertility uses, hCG has decades of use and label data behind it. One IVF trial included about 300 women. The lab-made version helped eggs mature as well as the standard urine-based product. A 2005 study looked at 29 healthy men given testosterone. Taking testosterone shuts down the body’s own LH. Low doses of hCG every other day for three weeks kept testosterone inside the testes in the normal range. For male infertility, a 2025 review pooled 7 trials with 926 men. In men with low sperm counts, treatment that included hCG made pregnancy about 3 times as likely. But the authors said the evidence was not convincing.
For weight loss, the results point the other way. A diet plan called the Simeons method paired hCG shots with a very-low-calorie diet. Controlled trials tested this. One 1976 study had 51 women on a 500-calorie diet. Some got hCG shots and some got dummy shots (placebo). hCG gave no extra weight loss. A 1995 review of 24 studies found no scientific proof that hCG helps treat obesity. The FDA has said any weight lost comes from eating very few calories, not from hCG.
Fertility: Chang et al. (Fertil Steril 2001) randomised 297 ovulatory women undergoing IVF to recombinant hCG 250 µg SC, 500 µg SC or urinary hCG 10,000 USP units IM; mean oocytes retrieved were 13.6, 14.6 and 13.7, with more fertilised oocytes but a trend to more adverse events at 500 µg. The Ovidrel label reports clinical pregnancy in 35.1% per initiated ART cycle and ovulation in 91.9% in ovulation-induction trials.
Male physiology: Coviello et al. (JCEM 2005) gave 29 men testosterone enanthate 200 mg weekly plus hCG 125, 250 or 500 IU every other day or placebo for 3 weeks. LH and FSH fell to 5% and 3% of baseline; intratesticular testosterone ended 25% below, 7% below and 26% above baseline, respectively. Male infertility: Shoaib et al. (Cureus 2025;17(10):e94003; 7 RCTs, 926 men, searched to December 2019) found hCG-combined treatment associated with higher pregnancy odds in oligospermia (OR 2.91, 95% CI 1.57–5.38) but concluded there is a “lack of compelling evidence”; no dose data were extractable. In a retrospective series of 152 men with non-obstructive azoospermia given clomiphene 25 mg plus hCG 2,000 IU SC three times weekly for at least 3 months before micro-TESE, sperm retrieval was 45% vs 50% without pretreatment (p=0.53; Al-Zubi et al., Front Reprod Health 2026;8:1696244). Two registered trials opened in 2026: a Phase 2 comparison of hCG 2,000 units SC three times weekly with oral isotretinoin in oligospermia and azoospermia (NCT07481370, University of Nebraska) and an early Phase 1 study of Ovidrel 125 mcg SC twice weekly for rehabilitation after brain injury (NCT07557615, VA).
Obesity: Stein et al. (Am J Clin Nutr 1976; n=51 women, double-blind, 32 days) repeated the 500 kcal diet of a 1973 positive study with hCG or placebo injections and found no difference in weight loss, girth or hunger. Lijesen et al. (Br J Clin Pharmacol 1995) scored 8 controlled and 16 uncontrolled trials; of the 12 better-quality studies only one reported benefit, and the authors found no evidence that hCG causes weight loss or fat redistribution.
Regulatory picture
There are three separate points here.
Approval: hCG is FDA approved. It needs a prescription and is given as a shot. It is approved for fertility treatment, for some men whose pituitary makes too little hormone, and for undescended testicles in boys. It is not approved for weight loss. No hCG product is approved for use without a prescription.
Compounding (pharmacies mixing their own versions): Since March 2020, hCG has been treated as a biological product. The FDA told pharmacies that biological products cannot be compounded under the usual pharmacy rules. They can only be mixed or diluted under narrow conditions.
Enforcement: In 2011, the FDA and the Federal Trade Commission warned seven companies. These companies sold “homeopathic” hCG diet drops. The FDA has also warned the public to avoid hCG diet products.
Approval: approved. Urinary hCG (Pregnyl, Novarel and generics) is labelled for prepubertal cryptorchidism not due to anatomic obstruction, selected hypogonadotropic hypogonadism in males, and ovulation induction in anovulatory women pretreated with gonadotropins; Ovidrel for final follicular maturation in ART and ovulation induction. The urinary hCG labels state in capitals that hCG has not been demonstrated to be effective adjunctive therapy in the treatment of obesity, with no substantial evidence of weight loss beyond caloric restriction or of effects on fat distribution or hunger.
Compounding: recorded as restricted. FDA’s 2020-03-05 notice named human chorionic gonadotropin among four bulk substances affected by the transition and stated that biological products are not eligible for the section 503A and 503B exemptions. FDA’s 2018 guidance on mixing, diluting or repackaging biological products outside the scope of a BLA describes limited conditions for manipulating a licensed product; it does not permit compounding from bulk hCG. FDA’s 503A nominations list (updated 2026-05-14) has no hCG entry, and no new FDA warning letter naming hCG was found for this update.
Enforcement: the 2011-12-06 joint FDA and FTC action targeted over-the-counter “homeopathic” hCG products; FDA’s consumer update (2020) states that hCG is not approved for weight loss or for use without a prescription. In sport, WADA’s 2026 list prohibits chorionic gonadotrophin in males under S2.2.1.
