FDA-APPROVED

hCG (Human Chorionic Gonadotropin)

A real FDA-approved hormone with legitimate fertility and male hypogonadism uses, and the same hormone behind one of medicine's most discredited weight-loss diets. The biology is real; the diet is not.

The 30-second read

hCG (human chorionic gonadotropin) is a hormone produced by the placenta during pregnancy. The FDA-approved drug version (brands include Pregnyl and Novarel) has been on the market for decades for legitimate clinical uses: treating female infertility (ovulation induction), male hypogonadism, and undescended testicles in boys. It's also been used off-label to maintain testosterone production during testosterone replacement therapy. Important to know up front: hCG also became famous as the "hCG diet", a discredited weight-loss program combining hCG injections with a 500-calorie-per-day diet. The FDA has explicitly stated the hCG diet is unsafe and ineffective; the FDA-approved hCG drugs are not approved for weight loss. Different uses, different evidence bases, very different conclusions.

Why this peptide is on people's radar

hCG has two distinct stories that often get conflated. The legitimate clinical story: hCG is a real FDA-approved hormone with several well-established uses. In women, it's used as the "trigger" injection in ovulation induction protocols and IVF cycles, and in some cases for treating infertility related to anovulation. In men, it's used to treat hypogonadotropic hypogonadism (low testosterone caused by problems upstream in the brain), to induce testicular descent in young boys, and increasingly off-label to maintain endogenous testosterone production while a man is on testosterone replacement therapy. These uses are well-evidenced, well-prescribed, and supported by decades of clinical experience.

The discredited story: the "hCG diet." Starting in the 1950s, British physician A.T.W. Simeons proposed that hCG injections combined with a 500-calorie-per-day starvation diet would produce dramatic, targeted fat loss while preserving muscle mass. The diet became a fad in subsequent decades and was repackaged in the 2000s as "homeopathic hCG drops" sold over the counter. The FDA has issued warning letters to companies marketing hCG for weight loss. Multiple randomized controlled trials have shown that hCG produces no weight-loss effect beyond what the 500-calorie diet alone produces. The 500-calorie diet itself is the dangerous component, it can cause gallstones, electrolyte imbalances, malnutrition, and other complications.

Both stories matter for understanding hCG. The first is real medicine. The second is the kind of thing the FDA explicitly warns people about. Anyone hearing "hCG" in different contexts is hearing about very different things.

What people are usually trying to do with it

Legitimate clinical uses include:

Inducing ovulation as part of fertility treatment (women)
Triggering oocyte maturation in IVF cycles (women)
Treating hypogonadotropic hypogonadism (men with brain-axis low T)
Inducing testicular descent in young boys with cryptorchidism
Maintaining endogenous testosterone production during TRT (off-label, common)

What the science actually shows

Plain-English summary:

Ovulation induction (FDA-approved, clinically established)

hCG mimics LH (luteinizing hormone), triggering final oocyte maturation and ovulation. Standard component of fertility treatment protocols for decades.1

Male hypogonadism (FDA-approved, clinically established)

For men with hypogonadotropic hypogonadism, hCG stimulates testicular Leydig cells to produce testosterone, restoring fertility-preserving testosterone production where direct TRT would not.2

Maintaining testicular function during TRT (off-label, common)

TRT typically suppresses LH, which causes testicular shrinkage and stops endogenous testosterone production and sperm production. Adding low-dose hCG during TRT preserves testicular function and fertility.3

Weight loss, does NOT work

Multiple randomized controlled trials have demonstrated that hCG injections produce no weight loss beyond what the very-low-calorie diet alone produces. The FDA has issued explicit warnings against marketing hCG for weight loss.4

What hasn't been demonstrated

Any meaningful weight-loss effect. Any "fat-targeting" or "metabolism-resetting" effect of hCG independent of caloric restriction. Safety of homeopathic OTC hCG products (which the FDA has identified as illegal).

The honest read

What's solid:

The legitimate fertility and hypogonadism uses of hCG are well-established and clinically valuable. As a TRT-adjunct for preserving testicular function and fertility, the evidence is real and the practice is increasingly mainstream in men's health.

What's a real concern:

The hCG diet is dangerous. Both because the 500-calorie diet itself causes complications (gallstones, electrolyte imbalances, malnutrition) and because using it gives people the false impression they're getting weight-loss benefits from the hormone when they're really just starving themselves. The FDA's warnings on this are not bureaucratic noise, they reflect real harm.

What's hyped beyond the evidence:

Anything framing hCG as a weight-loss aid. The placebo-controlled evidence is unambiguous: it doesn't work for that. Also: "homeopathic hCG drops" sold over the counter, the FDA has specifically warned that these are illegal products and that real hCG cannot be sold without a prescription.

Things to know if you're looking into it

Prescription only: hCG is FDA-approved as a prescription medication. Over-the-counter "homeopathic hCG drops" are not legitimate products.
The legitimate uses are well-defined: fertility treatment, male hypogonadism, undescended testicles, and as a TRT adjunct for preserving testicular function.
The hCG diet doesn't work: RCTs have repeatedly shown hCG produces no weight-loss effect beyond what the very-low-calorie diet produces. The FDA has issued specific warnings.
Used clinically as injection: intramuscular or subcutaneous, dosed by the prescribing clinician based on indication.
Not on the FDA Category 2 list (the list applies to compounding, and hCG has FDA-approved drug products available, so the regulatory situation is different).
Healthcare provider involvement: essential. hCG is a real prescription drug used for real medical conditions; clinical guidance is the standard pathway.
Specific dosing protocols, mechanism, and the full reference list: all in the "Want to go deeper?" section below.

Reconstitution & dose calculator

FDA-approved prescription drug. Universally dosed in IU (international units), not mg. The calculator below covers the typical TRT-adjunct use case (preserving testicular function alongside testosterone replacement therapy), which is the most common reason research-peptide and clinical hCG users encounter dose math. Single-dose ovulation-trigger use (5,000–10,000 IU as a one-time injection) is a different clinical context handled by a reproductive endocrinologist. hCG used alongside TRT requires clinical supervision — estradiol and testosterone monitoring matters. This is an educational reference, not dosing guidance.

TRT-adjunct start

250 IU/dose

Lower end; assess response with labs

Common range

250–500 IU/dose

2–3× weekly under TRT supervision

Higher community dose

1000 IU/dose

PCT context or aggressive TRT-adjunct; estradiol watch

Cadence

2–3× week

Continuous under medical supervision

Vial size

Bacteriostatic water

mL

Defaults to 1,000 IU/mL on both vials (5 mL into 5,000 IU; 10 mL into 10,000 IU) — the standard pharmacy convention. At this concentration, 250 IU = 25 syringe units, 500 IU = 50 units, 1000 IU = 100 units. If your vial can't hold the full water volume, drop to 2–3 mL for a more concentrated mix and the syringe units shrink proportionally.

Dose per injection

IU

Subcutaneous or intramuscular injection. Standard TRT-adjunct cadence is 2–3× weekly; the duration estimate below assumes 2× weekly. Eat normally around dosing — hCG doesn't have the empty-stomach considerations of GH peptides.

Concentration

1000 IU/mL

Per dose

0.25 mL

25 units on insulin syringe

Doses per vial

~20

~20 injections (~10.0 weeks) at 2× weekly

When to stay put vs. adjust

Stay put at 250 IU 2× weekly for the first 4–6 weeks while baseline labs (testosterone, estradiol, LH if not on TRT) catch up. The endocrine response to hCG is gradual at the receptor level — the testicular response builds over weeks, not days. The dose is appropriate when testicular function (size, fertility markers if applicable) is preserved without significant estradiol elevation.

Consider stepping to 500 IU 2–3× weekly if testicular preservation isn't holding at the lower dose AND estradiol remains within range on labs. The 250–500 IU range is where most TRT-adjunct community evidence sits. Above 500 IU per injection, you're getting more aggressive about testicular stimulation and the estradiol-elevation question becomes more relevant.

Don't go above 1000–1500 IU per injection for TRT-adjunct use. Higher doses don't reliably produce proportionally better testicular preservation, and they drive estradiol elevation through testicular aromatization — you can end up needing an aromatase inhibitor to manage what the hCG is creating. Some PCT (post-cycle testosterone restart) protocols use higher doses, but that's a different context with different goals.

Estradiol monitoring matters more than testosterone monitoring on hCG. Testosterone responds gradually; estradiol can climb faster than expected because the testicles aromatize testosterone to estradiol locally. Symptoms of high estradiol (mood changes, water retention, gynecomastia onset) should prompt a lab check before dose escalation. This is the most common reason TRT-adjunct hCG goes off the rails.

Storage matters more than for most peptides. Once reconstituted, hCG is stable for ~30 days refrigerated, but the activity declines noticeably toward the end of that window. Don't reconstitute a vial you won't finish in a month. The 5,000 IU vial gives ~20 doses at 250 IU which is right at the edge of the 30-day window if dosing 2× weekly — the 10,000 IU vial is more vial than most TRT-adjunct users will use before stability declines.

Hard contraindications: hormonally-influenced cancers (prostate, breast), known precocious puberty, prior allergic reaction. Caution with cardiovascular disease, kidney/liver disease, asthma, epilepsy, migraine. The cancer contraindication is real because hCG drives androgen production via the testicular pathway.

The honest read. hCG used as a TRT adjunct is one of the better-grounded research-community uses on this site — it's an FDA-approved prescription drug being used in a way that's pharmacologically coherent with its mechanism (LH-receptor agonism preserving testicular function during exogenous testosterone use). The clinical evidence base is solid for the approved indications (fertility, hypogonadism); the TRT-adjunct use is off-label but well-characterized in clinical practice. The "hCG diet" weight-loss use, by contrast, is the bad version — multiple RCTs show no weight-loss effect beyond the very-low-calorie diet itself, and the FDA has issued specific warnings. Don't confuse the legitimate TRT-adjunct math above with that. If you're considering hCG, you should be working with a clinician who orders labs and adjusts based on what the labs show.

For educational and research purposes only. This is not medical advice. hCG is FDA-approved as a prescription medication for fertility, hypogonadism, and undescended testicles. Use as a TRT adjunct or for post-cycle testosterone restart is off-label and requires clinical supervision with regular estradiol and testosterone monitoring. Hormonally-influenced cancers (prostate, breast) are hard contraindications. Consult a licensed healthcare provider before any health decision.

What people often ask

Does hCG work for weight loss?

No. Multiple randomized controlled trials have demonstrated that hCG produces no weight loss beyond what very-low-calorie diet alone produces. The FDA has issued warnings against marketing hCG for weight loss.

Is hCG FDA-approved?

Yes, for specific indications: female infertility (ovulation induction), male hypogonadotropic hypogonadism, and undescended testicles in boys. Brand names include Pregnyl and Novarel.

How is it used during testosterone replacement therapy?

Off-label, low-dose hCG is commonly used alongside TRT to maintain LH-like signaling at the testes, preserving testicular size, endogenous testosterone production, and (importantly for men who want it) fertility. This is increasingly mainstream in men's-health practices.

What about "homeopathic hCG drops"?

The FDA has specifically warned that homeopathic hCG drops sold OTC are illegal products. Real hCG is a prescription medication. "Homeopathic hCG" products either don't actually contain hCG or contain unregulated amounts.

Why does the hCG diet seem to work?

Because the 500-calorie-per-day diet causes weight loss. Anyone restricting calories that severely will lose weight regardless of whether they're injecting hCG or saline. RCTs that compared hCG plus the diet to placebo plus the diet found the same weight loss in both groups.

Are there side effects?

For legitimate clinical use, generally well-tolerated. Reported adverse effects include headache, fatigue, edema, and (in fertility-treatment contexts) ovarian hyperstimulation syndrome. In men on TRT-adjunct hCG, gynecomastia is occasionally reported at higher doses.

FDA and regulatory status

Status as of May 5, 2026: FDA-approved as Pregnyl, Novarel, and other brand names for: female infertility (ovulation induction), male hypogonadotropic hypogonadism, and prepubertal cryptorchidism. Not FDA-approved for weight loss. The FDA has issued specific warnings against the use of hCG for weight loss and against the marketing of homeopathic OTC hCG products. Off-label use during TRT is at the discretion of the prescriber.

Want to go deeper? Mechanism, dosing, and the hCG diet history.

Background

hCG is a glycoprotein hormone naturally produced by the placenta during pregnancy, with structural similarity to LH (both share a common alpha subunit; the beta subunit differs). FDA approval for fertility and hypogonadism uses dates to the 1970s and earlier. The hCG diet was originated by British physician A.T.W. Simeons in 1954 and has been repeatedly debunked in clinical trials over decades.

Mechanism of action

hCG binds the LH/hCG receptor on Leydig cells (in men) and theca cells (in women), mimicking LH's effects. In women, this triggers ovulation; in men, it stimulates testosterone production from Leydig cells.

Dosing for legitimate uses

Varies widely by indication. Fertility-protocol doses can be high (5,000–10,000 IU as ovulation trigger). TRT-adjunct doses are much lower (typically 250–500 IU two to three times per week). Always set by the prescribing clinician.

References

Lipscomb GH. (2003). "Human chorionic gonadotropin (hCG)." Clin Obstet Gynecol, 46(3), 661–668. PubMed
Coviello AD, Matsumoto AM, Bremner WJ, et al. (2005). "Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression." J Clin Endocrinol Metab, 90(5), 2595–2602. PubMed
Hsieh TC, Pastuszak AW, Hwang K, Lipshultz LI. (2013). "Concomitant intramuscular human chorionic gonadotropin preserves spermatogenesis in men undergoing testosterone replacement therapy." J Urol, 189(2), 647–650. PubMed
Lijesen GK, Theeuwen I, Assendelft WJ, Van Der Wal G. (1995). "The effect of human chorionic gonadotropin (HCG) in the treatment of obesity by means of the Simeons therapy: a criteria-based meta-analysis." Br J Clin Pharmacol, 40(3), 237–243. PubMed
U.S. Food and Drug Administration. "FDA warns consumers about hCG weight-loss products." Various consumer warnings, 2011 onward. FDA.gov

For educational and research purposes only. This is not medical advice. hCG is FDA-approved as a prescription medication for specific clinical indications. The FDA has explicitly warned against the use of hCG for weight loss. PeptideLibraryHub is independent and does not sell peptides or accept money from anyone who does.