The pregnancy hormone and an LH look-alike; FDA-approved for male hypogonadism and ovulation, and proven useless for weight loss.
Also called Human chorionic gonadotropin, Pregnyl, Novarel, Ovidrel, Choriogonadotropin alfa, Chorionic gonadotropin
hCG is the hormone that pregnancy tests detect. The placenta makes it to keep the ovary producing progesterone in early pregnancy. It is a large two-part glycoprotein, not a small peptide, and it acts almost exactly like LH: in men it tells the Leydig cells in the testes to make testosterone, and in women it can trigger the final step before ovulation.
In medicine hCG is an old, approved drug. Pregnyl and Novarel are purified from pregnancy urine and injected into muscle; Ovidrel is a recombinant version injected under the skin. Labeled uses are undescended testes in boys, low testosterone caused by pituitary failure in men, and triggering ovulation in fertility treatment. Men's clinics also give low doses alongside testosterone therapy to keep the testes making testosterone and sperm. That is off-label, and the evidence is a 29-man hormone study and a 26-man chart review, not a randomized fertility trial.
hCG is also the center of the 'hCG diet', a 500-calorie-a-day plan from the 1950s. Controlled trials found people lost the same weight on placebo injections, and the Novarel and Pregnyl labels state hCG has no known effect on fat, appetite or hunger. Since March 23, 2020, FDA has regulated hCG as a biologic, which ended compounding pharmacy production. WADA bans it in male athletes.
What it binds to, and what happens inside the body after that, step by step.
hCG binds the same receptor as LH, the LH/choriogonadotropin receptor (LHCGR), on Leydig cells in the testes and on ovarian follicle and corpus luteum cells. In men that drives testosterone production inside the testes, which sperm production depends on. In women a large dose mimics the mid-cycle LH surge, finishing egg maturation and triggering ovulation about 36 hours later. Because it bypasses the brain and pituitary, it works even when the pituitary has been shut down by testosterone therapy.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
hCG is an established fertility and hypogonadism drug backed by decades of use and many randomized trials in IVF. For men with pituitary-caused hypogonadism, gonadotropin therapy produces sperm in about 75% of cases. Its off-label use to preserve testicular function on testosterone therapy rests on small studies, and controlled trials show it does nothing for weight loss.
44 studies of men with hypogonadotropic hypogonadism and no sperm
Gonadotropin therapy produced sperm in 75% (95% CI 69 to 81%), with better results when hCG and FSH were combined.
Read the study18 RCTs, 2,952 women undergoing IVF or ICSI
No conclusive difference in ongoing pregnancy or live birth between recombinant and urinary hCG triggers.
Read the study29 healthy men on 200 mg testosterone enanthate weekly, 3 weeks
Testicular testosterone fell 94% on placebo; with 250 IU hCG every other day it stayed within 7% of baseline.
Read the study26 hypogonadal men on testosterone plus 500 IU hCG every other day, retrospective
No man became azoospermic over about 6 to 12 months, semen measures did not change, and 9 contributed to a pregnancy.
Read the study8 controlled and 16 uncontrolled trials
Of 12 better-quality studies, only 1 found hCG helpful; the authors concluded there is no evidence it causes weight loss, fat redistribution or less hunger.
Read the studyAdults with obesity on the Simeons diet, double-blind
Weight loss was identical on hCG and placebo injections, with no difference in hunger, mood or spot measurements.
Read the studyNo preclinical studies are listed as key studies here. The human data above carries the evidence.
These are questions the published research has not answered.
All approved hCG products now carry biologics licenses. The Novarel and Pregnyl labels state in capital letters that hCG has not been shown to be effective for obesity. FDA and the FTC declared over-the-counter 'homeopathic' hCG diet drops illegal in 2011. WADA prohibits chorionic gonadotrophin in males at all times (S2.2.1); it is not prohibited for female athletes.
How much of hCG (Human Chorionic Gonadotropin) is left after a single dose
Simple first-order model from the published half-life. Real clearance varies with dose, route, kidney and liver function and formulation. This is not a dosing schedule.
This table records the doses that trials and approved labels used, with the source for each row. It is a record of research, not a recommendation, and it is open to free members.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
Double-blind trials found the same weight loss on placebo injections, a 1995 meta-analysis found no benefit, and the Novarel and Pregnyl labels say hCG has no known effect on fat or hunger. The weight loss comes from eating 500 calories a day.
FDA says all 'homeopathic' hCG products are illegally marketed. hCG is only approved as a prescription injection, and it is not absorbed under the tongue.
In 29 men on testosterone, 250 to 500 IU every other day kept testicular testosterone near normal, and in a 26-man series no one became azoospermic. These are small studies, not fertility RCTs.
It is widely used for this, but no controlled trial has measured recovery of the body's own testosterone with versus without hCG.
Since March 23, 2020, hCG has been a licensed biologic and US compounding pharmacies can no longer make it.
These pairings come up often. Almost none have been tested together in a trial, and the evidence note on each says so plainly.
Testosterone suppresses LH and FSH; hCG replaces the LH signal so the testes keep making testosterone and, likely, sperm.
EvidenceSupported by a 29-man, 3-week hormone study and a 26-man retrospective series. No randomized trial with pregnancy as the outcome.
Novarel powder is stored at room temperature, 20 to 25°C (68 to 77°F). Pregnyl unopened vials at 15 to 25°C. Ovidrel prefilled syringes are refrigerated at 2 to 8°C until dispensed.
Novarel mixed with bacteriostatic water: refrigerate at 2 to 8°C (36 to 46°F) and use within 30 days. Pregnyl: refrigerate at 2 to 8°C and discard after 60 days. Both per their labels.
One email when a trial reads out, a label changes or the FDA acts on a peptide. Free, no selling of peptides, unsubscribe any time.