Does the hCG diet work?

The diet produces weight loss. The hCG contributes nothing to it. Trials matching calories found no difference from placebo, and the FDA requires labelling saying it is not effective for weight loss. What you are doing is eating 500 calories a day, which is a supervised medical intervention when done properly and is not made safer by an injection.

Why is it used with testosterone?

Exogenous testosterone suppresses the pituitary signal that tells the testes to work, so they shrink and sperm production stops. hCG mimics that signal directly, keeping them stimulated. It is standard endocrine practice, and it is usually prescribed alongside monitoring rather than added independently.

Will it make a pregnancy test positive?

Yes. hCG is exactly what a pregnancy test detects, and it takes days to clear.

Muscle & performance

HCG

Human chorionic gonadotropin · Chorionic gonadotropin · hCG · Pregnyl · Ovidrel

ApprovedProhibited in sportReviewed 18 Aug 2026

Human chorionic gonadotropin is a hormone produced in pregnancy and the thing a pregnancy test detects. As a medicine it has been approved for decades, used to trigger ovulation in fertility treatment and to treat hypogonadotropic hypogonadism and undescended testes.

Its most common non-fertility use is alongside testosterone replacement. Exogenous testosterone shuts down the pituitary signal that tells the testes to work, causing them to shrink and stopping sperm production. hCG mimics LH directly, keeping the testes stimulated while that signal is absent. This is genuine, widely practised endocrinology, though usually prescribed rather than improvised.

It is also sold for the hCG diet: a 500-calorie-a-day regimen with hCG injections or drops. The FDA has stated plainly that hCG is not effective for weight loss — requires labelling to that effect — and has taken action against the homeopathic products. Any weight lost on that protocol is lost because of the 500 calories, and starving on a hormone is not different from starving.

How it works

hCG binds the LH receptor. In men that drives Leydig cells to produce testosterone locally in the testes. It is why testicular size and spermatogenesis hold up when the pituitary signal has been suppressed.

In women it triggers ovulation by mimicking the LH surge, which is its fertility indication.

Its half-life is far longer than LH's, which is why it is dosed a few times weekly rather than continuously.

It has no known mechanism relating to fat metabolism. That is the core of the FDA's position on the diet: not that the evidence is weak, but that there is no basis for the claim at all.

Quick reference

Commonly described dose: 250 mcg–500 mcg
How often: Two to three times weekly
Route: Subcutaneous or Intramuscular
Where: Abdomen, Thigh
Timing: Spread across the week for maintenance use; timed to the cycle for fertility use.
Storage once mixed: Refrigerated, 30 days

These describe what sources report, not what you should do. Full detail and provenance in the dosing section below.

Price index

Per-milligram pricing across vendors arrives with the directory. We are recording prices now so the history exists when the page ships.

Vocabulary on this page

IU: An international unit: a measure of biological activity, not of mass. How many milligrams an IU corresponds to depends entirely on the substance.
Intramuscular: Into muscle rather than the fat beneath the skin. A faster and better-perfused route, needing a longer needle.
Unit: A mark printed on an insulin syringe. A unit is not a fixed volume. What it represents depends entirely on the syringe's scale.
Half-life: The time it takes for half of a compound to be cleared from the body.
Injection site: Where on the body an injection is given. Rotating between sites is standard practice for anything given repeatedly.

The whole glossary →

Regulatory status — United States

Approved by the FDA and EMA as a prescription medicine for fertility and hypogonadism indications. Labelling is required to state that it is not effective for weight loss, and the FDA has acted against homeopathic hCG weight-loss products.

Last reviewed 18 Aug 2026. Regulatory positions in this category change frequently; we date this line so you can see how current it is.

What it is studied for

Each entry states the evidence behind it. We do not rank indications by effectiveness — for most compounds here, that would be a claim nobody can support.

Ovulation induction in fertility treatment

Published review

A core approved indication.

EvidenceDecades of clinical use and trial evidence.

Hypogonadotropic hypogonadism and undescended testes

Published review

Approved indications in males.

EvidenceApproved on trial evidence.

Maintaining testicular function during testosterone therapy

Clinical trial

Common prescribed off-label use.

EvidenceWell-established endocrine practice, supported by studies showing preserved intratesticular testosterone and spermatogenesis.

Weight loss

Published review

Not effective, and the FDA says so directly.

EvidenceControlled trials found no difference from placebo when calories were matched. The FDA requires labelling stating it is not effective for weight loss.

Identity and clearance

Molecule

Class: Glycoprotein hormone, alpha and beta subunits
Molecular weight: 36700 Da

Shares its alpha subunit with LH, FSH and TSH; the beta subunit gives it specificity.

Dose protocols reported in sources

Displayed for reference only. Every row says where it came from, and a trial protocol and a community convention are not the same kind of information. None of this is fed into the calculator, and none of it is a recommendation.

Dose protocols reported in sources, with the source of each.
Goal	Dose	Frequency	Route	Units	Source	Start this protocol
Maintaining testicular function alongside testosterone therapy	250 mcg – 500 mcg	Two to three times weekly	SubcutaneousExpressed here in international units rather than micrograms: roughly 250 to 500 IU per injection. hCG is dosed in IU throughout the literature, and converting it to a mass figure is where errors happen.	—	Clinical trial	Start this
Ovulation trigger	5 mg – 10 mg	A single dose, timed to the cycle	IntramuscularAgain in international units. A single timed trigger, given in a fertility clinic against ultrasound monitoring.	—	Published review	Start this

Start this copies a row into a protocol of your own, which you can then edit. Where a source gave a dose range or an ambiguous frequency, those fields arrive empty — we will not pick a number on your behalf.

Safety

Reported effects

Raised oestrogen and gynaecomastia in menClinical trial
Common at higher doses
Stimulating the testes raises testosterone locally, some of which aromatises. This is the most common reason a maintenance dose is reduced.
Ovarian hyperstimulation syndromePublished review
Uncommon, and potentially serious
In fertility use. Ranges from abdominal discomfort to a medical emergency. That is why fertility clinics monitor with ultrasound before triggering.
Injection site reactionsPublished review
Common
Mood changes, headache, fatiguePublished review
Reported
Multiple pregnancyPublished review
Increased with ovulation induction

When to stop

Breast tenderness or enlargement in men. That is a sign oestrogen has risen.
Severe abdominal pain, bloating, rapid weight gain or breathlessness after a fertility trigger. This can be ovarian hyperstimulation and needs urgent assessment.
Leg pain or swelling, chest pain or breathlessness. Clot symptoms.
Any allergic response: rash, hives, facial swelling or difficulty breathing. Seek urgent care.

Interactions and situations that need care

Hormone-sensitive cancer, including prostate and breastAvoid
It raises testosterone and downstream oestrogen. Contraindicated in the prescribing information.
Precocious pubertyAvoid
Contraindicated in the prescribing information.
The hCG weight-loss dietAvoid
The hormone does nothing for weight loss. That is the FDA's stated position, and controlled trials with matched calories found no difference from placebo. What the protocol does provide is 500 calories a day, which is a very low calorie diet that in medical settings requires supervision because of gallstones, electrolyte disturbance and cardiac risk. The injections give it a medical appearance it has not earned.
Pregnancy and breastfeedingAvoid
No indication for use once pregnancy is established. Note that hCG is what a pregnancy test detects, so taking it produces false positives.
Competing in a tested sport, if maleAvoid
WADA class S2, prohibited at all times in males, precisely because it raises endogenous testosterone.

SportProhibited by the World Anti-Doping Agency under S2: Peptide Hormones, Growth Factors, Related Substances, at all times in males; not prohibited in females. Prohibited in males precisely because it raises endogenous testosterone. The sex-specific scope is unusual and is stated that way in the list.

What to expect

For fertility and for maintaining testicular function during testosterone therapy, this is well-established medicine.
For weight loss it does nothing. The FDA requires the label to say so, and matched-calorie trials found no difference from placebo.
It is dosed in international units, not milligrams. This site's calculator works in mass and does not apply.
Taking it makes a pregnancy test read positive, which surprises people.
Raised oestrogen is the usual reason a dose gets reduced, and it is manageable when someone is monitoring it.

Storage and handling

Freeze-dried powder: Refrigerated at 2–8 °C, or per the manufacturer's label.
After mixing: Refrigerated at 2–8 °C and used within about 30 days, or as the label states.
Long-term, frozen: Not recommended.

Printable one-pager How to reconstitute a vial, step by step

With other peptides

Testosterone (TRT)synergistic
The standard pairing. This replaces the pituitary signal that testosterone suppresses, maintaining testicular size and sperm production. Normally prescribed together rather than added independently.
Gonadorelincaution
Both are used to keep the gonadal axis running during testosterone therapy, but at different points. Gonadorelin acts on the pituitary; hCG bypasses it and acts on the testes. Using both is redundant rather than additive, and it is a prescribing decision.
Kisspeptin-10caution
Both stimulate the same axis, kisspeptin from further upstream. Combining them stacks a signal that is already being deliberately manipulated.

Check this against a whole stack

Checking your vial

Research chemicals carry no manufacturing standard, so what the vial looks like is often the only quality signal available before you use it. More on assessing quality and COAs.

Clear solution after reconstitution
Normal.
Cloudiness or particles
Discard it.
Homeopathic drops sold for weight loss
These contain essentially no hCG, and the FDA has acted against them. The 500-calorie diet they accompany is what produces the weight loss, and that part is not benign.

Questions

Does the hCG diet work?: The diet produces weight loss. The hCG contributes nothing to it. Trials matching calories found no difference from placebo, and the FDA requires labelling saying it is not effective for weight loss. What you are doing is eating 500 calories a day, which is a supervised medical intervention when done properly and is not made safer by an injection.
Why is it used with testosterone?: Exogenous testosterone suppresses the pituitary signal that tells the testes to work, so they shrink and sperm production stops. hCG mimics that signal directly, keeping them stimulated. It is standard endocrine practice, and it is usually prescribed alongside monitoring rather than added independently.
Will it make a pregnancy test positive?: Yes. hCG is exactly what a pregnancy test detects, and it takes days to clear.

References

Chorionic gonadotropin: FDA prescribing information
US Food and Drug Administration, 2024 · Regulatory label
Fertility and hypogonadism indications
Approved for ovulation induction, hypogonadotropic hypogonadism and prepubertal cryptorchidism. Labelling is required to state that hCG has not been demonstrated effective for weight loss or fat redistribution, and that there is no substantial evidence it increases weight loss beyond that from calorie restriction alone.
Low-dose hCG maintains intratesticular testosterone during exogenous testosterone administration
Journal of Clinical Endocrinology and Metabolism, 2005 · Randomised controlled trial
Healthy men receiving exogenous testosterone · 125 to 500 IU every other day
Low-dose hCG preserved intratesticular testosterone in a dose-dependent manner during exogenous testosterone administration, supporting its use to maintain testicular function and spermatogenesis.
10.1210/jc.2004-1802
Community and clinic practice, unverified
Forums, coaching protocols and wellness-clinic marketing, 2026 · Anecdote
Self-selected, unverified
Doses and schedules described outside medical supervision. No study design, no adverse event capture, and heavy selection bias.

Related compounds

Testosterone (TRT)

Not a peptide, and the most consequential thing on this site. Approved replacement therapy for diagnosed hypogonadism — a Schedule III controlled substance — and something that will make you infertile while you take it.

Gonadorelin

Natural GnRH, approved as a diagnostic agent. Widely used alongside testosterone therapy on a rationale that is sound in principle and unstudied in that setting.

Kisspeptin-10

The master switch above the reproductive hormone axis. Unusually for this category, it has a serious academic research programme in humans behind it.

Ipamorelin

A selective growth hormone secretagogue that prompts a short pulse of GH release. Widely used, and supported almost entirely by early pharmacology rather than outcome trials.

Keep this page honest

If something here is wrong, out of date, or missing a source, tell us and we will fix it and say that we did.

Suggest a correction

This page is educational. It describes what published research reports, not what you should do. Peptides discussed here are largely not approved for human use, and nothing on Bioalmanac is medical advice. No clinician reviews these pages.

Page last updated 18 Aug 2026

HCG

How it works

What it is studied for

Ovulation induction in fertility treatment

Hypogonadotropic hypogonadism and undescended testes

Maintaining testicular function during testosterone therapy

Weight loss

Identity and clearance

Dose protocols reported in sources

Safety

What to expect

Storage and handling

With other peptides

Checking your vial

Questions

References

Related compounds

What to do with HCG

Keep this page honest