What is HCG? What it does, benefits and what the evidence shows

Human chorionic gonadotropin (HCG) is a hormone made by the placenta that acts almost exactly like the pituitary hormone LH. It is an approved prescription drug in the US, sold as Novarel and Pregnyl and as a generic, for three things: prepubertal undescended testicles, selected cases of low testosterone caused by a pituitary problem in men, and inducing ovulation in certain infertile women. It is not approved for weight loss, and FDA labels say there is no substantial evidence that it works for that. Many grey-market buyers want it for a different reason: to stimulate the testes alongside testosterone or anabolic steroids, which is the use the trial evidence covers least.

What HCG is and how it works

HCG is not a short peptide like most compounds on our site. It is a glycoprotein, built from an alpha and a beta subunit. Its label describes the alpha subunit as essentially identical to that of the pituitary hormones LH, FSH and TSH, with the beta subunits differing in amino acid sequence (DailyMed, Novarel label). The approved products are made from the urine of pregnant women: the Novarel label calls it "a water soluble glycoprotein derived from human pregnancy urine," and Pregnyl's says it is obtained from the urine of pregnant persons (DailyMed, Pregnyl label).

What it does: the label says its action is virtually identical to LH, with a small degree of FSH activity as well. In men it stimulates the Leydig cells of the testes to make androgens. In women it stimulates the corpus luteum to make progesterone, and it can stand in for the mid-cycle LH surge that triggers ovulation (DailyMed, Novarel label). In other words, it doesn't ask the body to make its own LH; it does LH's job directly. That is the practical difference from gonadorelin, which acts higher up, on the pituitary.

Because it is a large, complex molecule, HCG comes in several molecular forms rather than one uniform structure, with differences in the protein core and sugar branches (de Medeiros and Norman, Human Reproduction Update, 2009). That is one reason a single purity percentage is a blunter tool for HCG than for a short peptide.

US approval status

• Approved, current labels. Novarel's label lists "Initial U.S. Approval: 1974" and its DailyMed listing was updated on September 25, 2025. Pregnyl's label was revised in March 2025. A generic chorionic gonadotropin from Fresenius Kabi is also listed (DailyMed, Novarel; Pregnyl; Fresenius Kabi).
• Now regulated as a biologic. Under a legal change on March 23, 2020, existing chorionic gonadotropin applications, including Pregnyl, Novarel and generics, were deemed biologics license applications (FDA list of transitioned products).
• Not approved for weight loss. The label's indications section opens with a warning that HCG "has not been demonstrated to be effective adjunctive therapy in the treatment of obesity." In 2011, FDA and the FTC sent warning letters to sellers of over-the-counter "homeopathic" HCG weight-loss products, stating that there are no FDA-approved HCG drug products for weight loss (FDA news release, December 6, 2011).

What people use it for

What the research actually shows

Men with a pituitary-related testosterone deficit

The label lists "selected cases" of hypogonadotropic hypogonadism in males as an approved use. The bigger evidence base is about sperm production. A 2025 meta-analysis of 41 studies with 1,673 men who had gonadotropin deficiency found that treatment with gonadotropins produced some sperm in most patients (78% reached a sperm concentration above zero), but higher sperm outputs, closer to those usually needed for a natural pregnancy, were reached less often (about 24% of men above 10 million per milliliter). Combined HCG plus FSH did better than HCG alone for sperm output, while the two approaches raised testosterone and testicular volume similarly (Muir et al., 2025). A 2018 review noted that HCG alone tends to work for men who developed normally and lost their signal in adulthood, and rarely for men with congenital deficiency, who usually need FSH as well (Prior et al., Clinical Endocrinology, 2018). These are results from men with a diagnosed pituitary or hypothalamic problem under specialist care, not from healthy men.

Ovulation and fertility treatment

HCG is the long-standing trigger for final egg maturation in IVF cycles. A Cochrane review of 18 randomized trials with 2,952 women (15 comparing recombinant HCG with the urinary product and 3 comparing recombinant LH) found no conclusive difference in ongoing pregnancy or live birth between recombinant HCG and the urinary product, and no evidence of a difference in ovarian hyperstimulation rates (Youssef et al., 2016). The Pregnyl label frames ovulation induction as treatment for anovulatory women who have been appropriately treated with human gonadotropins, requiring monitoring with blood tests and ultrasound (DailyMed, Pregnyl label). It is a clinic-supervised drug in this setting.

Testosterone and anabolic steroid users

A review of gonadotropins in sport states that HCG stimulates testosterone production in males, and that its main use among athletes is probably to stimulate the testes' own testosterone production alongside testosterone or anabolic steroids; the same review notes that use of gonadotropins is prohibited in male athletes, and that a benefit for muscle strength has not been demonstrated in women (Stenman et al., British Journal of Pharmacology, 2008). That is the demand this market responds to.

The best-controlled human data are physiology studies, not outcome trials. In 29 healthy men whose gonadotropins had been suppressed with testosterone, intratesticular testosterone fell 94% without HCG, and HCG maintained it; the study measured hormone levels in testicular fluid, not sperm counts or fertility (Coviello et al., JCEM, 2005). A separate study of 18 power athletes using large amounts of anabolic steroids together with HCG found a transient impairment in semen quality, with larger HCG amounts correlating with more abnormally shaped sperm (Karila et al., International Journal of Sports Medicine, 2004). We won't say how anyone should use HCG in this setting. The evidence supports the hormonal effect and does not support a strategy or a safe way to do it.

Weight loss

The "HCG diet" combines injections with a very low calorie intake. A criteria-based meta-analysis of eight controlled and 16 uncontrolled trials found most were of poor quality, and among the 12 better-scoring studies (all controlled) only one reported HCG as useful; the authors concluded there was no scientific evidence that HCG works for obesity (Lijesen et al., 1995). The label goes further: it says HCG has no known effect on fat mobilization, appetite or body fat distribution (DailyMed, Novarel label). FDA also pointed out that people on a very low calorie diet face a higher risk of gallstones, electrolyte imbalance and heart arrhythmias, and that this diet should be medically supervised (FDA, 2011).

Side effects and risks

From the approved labels, which describe supervised medical use:

• Common reactions. Headache, irritability, restlessness, depression, fatigue, edema, precocious puberty, gynecomastia and pain at the injection site. Localized and systemic hypersensitivity reactions have been reported (DailyMed, Novarel label).
• Anaphylaxis. The labels state that anaphylaxis has been reported with urinary-derived HCG products (DailyMed, Pregnyl label).
• Women in fertility treatment. Ovarian hyperstimulation, ovarian cyst rupture with internal bleeding, multiple births and arterial thromboembolism (DailyMed, Fresenius Kabi label).
• Who shouldn't take it. The labels list precocious puberty, prostate cancer or other androgen-dependent tumors, and prior allergic reaction among the contraindications, and warn HCG may cause fetal harm in pregnancy (DailyMed, Novarel label).
• Testicular tumor reports. The Novarel label mentions sporadic reports of testicular tumors in otherwise healthy young men receiving HCG for secondary infertility, and says a causal relationship has not been established.
• Lab-test interference. HCG can cross-react in gonadotropin assays, especially for LH, so labs should know if you are on it (DailyMed, Novarel label).
• Sport. The gonadotropin review above states use is prohibited in male athletes (Stenman et al., 2008); check the current anti-doping list if it applies to you.

None of this tells you how a vial of unknown origin behaves. The approved products at least come with an FDA-reviewed label; a vial of unknown origin doesn't.

What the lab tests show

As of September 29, 2026, VendorVerify's database has one HCG vial (February 2026). The lab report gave no purity figure. The measured amount, which the vial labeled in international units (IU), came in about 13% over label. That is a single sample; it says nothing reliable about any vendor or batch. If you have had HCG tested, submitting the report adds to it.

Because we don't have enough lab data on this compound to rank vendors for it, here are the highest-ranked vendors across all compounds right now. A vendor's overall record is a signal, not a guarantee for a compound they have never had tested.

There's a results page for the compound too: see HCG on our peptide pages.

Buying smarter

Check how many reports sit behind any vendor's score in their full record, and treat a vendor-posted COA as a starting point (how to read a peptide COA, fake peptide COAs). Because HCG is a large glycoprotein sold in IU rather than milligrams, ask what the report actually measured and how; a bare purity number may not mean much here. Paying for a test of your own vial is worth it for a compound where our database has almost nothing (how to get a peptide tested), and endotoxin in research peptides covers when to add that test.

If a report comes back with a fail, stop using that batch, tell anyone who bought from the same run, bring the report to the vendor, and submit it to VendorVerify. The peptide hub lists every compound we track, and gonadorelin and kisspeptin-10 are the other reproductive-axis compounds people ask about.

Database figures are from VendorVerify as of September 29, 2026. This isn't medical advice; HCG sold outside a licensed setting is unregulated and sold for research use only, and its approved uses do not include weight loss.