At a glance: hCG is the "pregnancy hormone" made by the placenta. As a prescription drug (Pregnyl, Novarel, Ovidrel and generics) it is FDA-approved for fertility treatment, undescended testicles in boys and certain types of low testosterone in men. It is not effective for weight loss: the FDA and FTC declared over-the-counter "hCG diet" products illegal in 2011. Since 2020 it has been regulated as a biologic, so pharmacies can no longer compound it.
What is hCG?
Human chorionic gonadotropin (hCG) is a hormone made by the placenta shortly after an embryo implants. It is the hormone that home pregnancy tests detect. Unlike most compounds on this site it is not a small peptide but a glycoprotein: two protein chains (alpha and beta) with sugar groups attached.
In pregnancy, hCG signals the ovary to keep producing progesterone and estrogen, which maintain the uterine lining and stop menstruation. Levels roughly double every two to three days in early pregnancy and peak around week 10. Tiny amounts are present in everyone.
How does hCG work as a medicine?
hCG closely resembles luteinizing hormone (LH), the pituitary hormone that controls the ovaries and testes, and acts on the same receptor:
- In women: it triggers the final maturation and release of eggs (ovulation), which is why it is used as a "trigger shot" in IVF and other fertility treatments, and it can support early pregnancy hormones
- In men: it stimulates the testes to make testosterone and supports sperm production
- In boys: it can help undescended testicles move down into the scrotum when there is no physical blockage
What the research shows
hCG has been used in medicine for decades, and its approved uses are well established:
| Use | Evidence | Status |
|---|---|---|
| Ovulation induction and IVF | Long-established clinical use and trials | FDA-approved |
| Low testosterone from pituitary or hypothalamic causes (hypogonadotropic hypogonadism) | Clinical studies show it raises testosterone and supports sperm production | FDA-approved |
| Undescended testicles in boys | Clinical use; surgery is often preferred today | FDA-approved |
| Preserving fertility or testicle size during testosterone therapy | Small studies and common clinical practice | Off-label |
| Weight loss ("hCG diet") | Placebo-controlled trials found no benefit beyond the very-low-calorie diet itself | Not effective; not approved |
hCG is also measured as a tumor marker: some testicular and ovarian germ cell tumors and pregnancy-related tumors produce it, so blood tests help diagnose and monitor them.
Why it gets attention
- Men's health clinics prescribe it alongside testosterone to preserve fertility and testicle size
- Fertility treatment, where it is a standard part of IVF
- The "hCG diet", which pairs hCG with a 500-calorie-a-day diet and has been marketed for decades despite the evidence
- Bodybuilding, where it is used after steroid cycles to restart natural testosterone production
How it is used
Prescription hCG is given by injection, into a muscle or under the skin depending on the product, on a schedule set by a fertility specialist, urologist or endocrinologist. Recombinant hCG (Ovidrel) comes in a prefilled syringe for fertility use. Drops, pellets and sprays sold over the counter as "homeopathic hCG" are not approved products. This page does not provide dosing guidance.
What about side effects?
From the FDA labels:
- Common: injection-site reactions, headache, fatigue, irritability and mood changes, and fluid retention
- Ovarian hyperstimulation syndrome (OHSS) in fertility treatment, where the ovaries swell and fluid shifts in the body; severe cases need urgent care
- Multiple pregnancy (twins or more) when used for ovulation induction
- Breast enlargement (gynecomastia) in men, because higher testosterone can convert to estrogen
- Early puberty when used in boys
- Blood clots and serious allergic reactions, which are rare
hCG should not be used during pregnancy once conception has occurred, and people with hormone-sensitive cancers, such as some prostate or breast cancers, need specialist review.
Regulatory status
- FDA-approved prescription drug for ovulation induction and assisted reproduction, hypogonadotropic hypogonadism in males, and prepubertal undescended testicles.
- Not approved for weight loss. The label states it is not an effective treatment for obesity. In December 2011 the FDA and FTC sent warning letters calling over-the-counter hCG diet products, including homeopathic drops and sprays, "unproven and illegal."
- Regulated as a biologic since March 2020. Because pharmacies cannot compound biologics, compounded hCG is no longer legally available; patients use FDA-approved products such as Pregnyl, Novarel, Ovidrel or generic chorionic gonadotropin.
- Banned in sport for men by the World Anti-Doping Agency, because it raises testosterone.
The bottom line
hCG is a well-understood hormone and a legitimate, FDA-approved medicine for fertility treatment and certain kinds of low testosterone. It is a useful tool when prescribed and monitored by a specialist. It does not cause weight loss, the hCG diet's results come from extreme calorie restriction, and over-the-counter hCG products are illegal. Anyone interested in hCG for fertility or hormone treatment should work with a qualified clinician.
Frequently asked questions
What is HCG?
A hormone made during pregnancy. It is a glycoprotein, a much larger molecule than most peptides on this site.
How is HCG taken?
Intramuscular injection.
Is HCG FDA approved?
FDA-approved (prescription) for specific fertility uses.
What has research shown about HCG?
- Triggering ovulation in fertility treatment.
- Low testosterone caused by pituitary problems in men.
- Weight loss: trials found no benefit, and its FDA label says it is not effective for weight loss.
What side effects have been reported?
- Headache
- Irritability and restlessness
- Tiredness
- Swelling
- Injection site pain
Serious or less common risks are listed in the Side Effects section above.
What is still unknown about its safety?
Side effects that are rare, or that only appear after many years of use, are still being tracked through post-marketing surveillance. Talk to a prescriber about your own risk.
References
- Cleveland Clinic: Human chorionic gonadotropin (hCG). View source
- PDR: Novarel (chorionic gonadotropin) drug summary, indications and adverse reactions. View source
- Relias Media: FDA vs hCG diet supplements (December 2011 FDA/FTC warning letters). View source
- Compounding Finder: hCG compounding status after the March 2020 biologics transition. View source
- World Anti-Doping Agency: 2026 Prohibited List. View source