What it is
Human chorionic gonadotropin is the hormone of early pregnancy. The placenta makes it to keep the ovary producing progesterone until the placenta can take over, and it is the molecule a home pregnancy test detects.
It is not a short peptide, and this entry says so first. hCG is a glycoprotein made of two chains:
- an alpha subunit of 92 amino acids (UniProt P01215, mature chain), and
- a beta subunit of 145 amino acids (UniProt P0DN86, mature chain),
237 residues in all, with sugar groups attached. It appears in this library because it is sold and searched alongside the peptides here, not because of its size.
The Novarel and Pregnyl labels both note that the alpha subunit is essentially identical to the alpha subunits of LH, FSH and TSH. The beta subunit is what makes it hCG — and it is close enough to LH's beta subunit that hCG switches on the LH receptor. Almost everything hCG is used for follows from that single fact.
What it is approved for
hCG is a prescription biologic in the United States. The two labels read for this entry are NOVAREL (BLA 017016, Ferring, label effective 2025-08-27) and PREGNYL (BLA 017692, Organon, label effective 2025-12-02). Both are purified from the urine of pregnant women.
Their approved indications are the same three:
- Prepubertal cryptorchidism not due to anatomical obstruction — testes that have not descended in young boys, usually treated between ages 4 and 9. The labels add that in most cases the response is temporary.
- Selected cases of hypogonadotropic hypogonadism in males — low testosterone caused by the pituitary not sending LH.
- Induction of ovulation in anovulatory infertile women whose ovaries themselves are not the problem, after pretreatment with other gonadotropins.
The sentence at the top of the label
Before either label lists a single approved use, it prints this — in capital letters:
HCG has not been demonstrated to be effective adjunctive therapy in the treatment of obesity.
It goes on: there is no substantial evidence that hCG increases weight loss beyond calorie restriction, causes a "more attractive or normal" distribution of fat, or decreases the hunger of a calorie-restricted diet.
It is unusual for a drug label to open by refuting a use. This one does because the use was common enough to need it. The "hCG diet" pairs hCG with an intake of around 500 calories a day.
FDA's consumer update on hCG diet products goes further. It says hCG is not approved without a prescription for any purpose and not approved for weight loss; that products sold as oral drops, pellets and sprays are illegal; and that very low-calorie diets carry risks of gallstones, electrolyte imbalance and irregular heartbeat. It quotes an official of its Office of Unapproved Drugs and Labeling Compliance: any loss is from severe calorie restriction, not from the hCG.
Why it is used with testosterone
The second large unlabelled market is men using testosterone or anabolic steroids.
External testosterone tells the pituitary to stop releasing LH. Without LH, the testes shrink and produce less testosterone and sperm of their own. Because hCG acts on the LH receptor, it can stand in for the missing signal. That reasoning follows directly from the hormone's biology, which is why it is plausible — and it is the same logic behind the approved hypogonadism indication.
It is still not an approved indication on the US labels read here, and the labels' regimens were written for pituitary deficiency and fertility, not for use alongside exogenous testosterone.
The dose figures on the labels
hCG is measured in USP units of biological activity, not milligrams. The labels do not give one standard dose; they list regimens "advocated by various authorities", and say the choice depends on indication, age, weight and physician preference. As printed (read 2026-09-17):
| Indication | Regimens listed on the label |
|---|---|
| Prepubertal cryptorchidism | 4,000 USP units three times weekly for three weeks · 5,000 units every second day for four injections · 15 injections of 500–1,000 units over six weeks · 500 units three times weekly for four to six weeks |
| Hypogonadotropic hypogonadism in males | 500–1,000 units three times a week for three weeks, then twice a week for three weeks · 4,000 units three times weekly for six to nine months, then 2,000 units three times weekly for three months |
Novarel comes as 5,000 and 10,000 USP unit vials, for intramuscular use only; its label specifies reconstitution with bacteriostatic water and refrigeration for up to 30 days. None of these regimens is for weight loss, and none is for use alongside testosterone.
Where it stands
A thoroughly studied hormone: PubMed indexes 41,204 chorionic gonadotropin records, 934 of them randomized controlled trials (E-utilities, 2026-09-17), most in fertility medicine. The approved uses are narrow and well established. The biggest consumer use — dieting — is the one its own labels reject.
Related entries in this library: native GnRH (gonadorelin) and its long-acting analogue triptorelin act one level higher, on the pituitary rather than the testes and ovaries; kisspeptin, the switch above the pituitary, sits above both. For GLP-1 drugs, which do have approvals for weight management, see the semaglutide record.
Last checked
2026-09-17. The current Novarel and Pregnyl labels were read through the openFDA API, UniProt entries P01215 and P0DN86 through the UniProt REST API, and FDA's consumer update on hCG diet products on fda.gov, all on that date, as were the PubMed counts.