HCG

Hormonal Approved · US, EU & worldwide Human trials

Also called Human chorionic gonadotropin, Chorionic gonadotropin

A hormone made by the placenta in pregnancy, and the hormone a pregnancy test detects. It closely mimics luteinising hormone, the pituitary signal that tells the testes to make testosterone, which is why it is used to switch testicular function back on.

Evidence at a glance

Evidence: Human trials — Studied in people
Status: An approved medicine in US, EU & worldwide
Dosing: A dose has been tested in humans

The fertility and cryptorchidism uses are approved and well evidenced. Its use alongside testosterone therapy is off-label, and the once-popular HCG diet is not supported: controlled trials found no weight loss beyond the severe calorie restriction it was paired with, and the FDA has acted against those products.

What studies report

Triggers ovulation in fertility treatment, in long-established human use
Restores testicular testosterone production and preserves testicle size during testosterone therapy, in controlled human studies
Maintains sperm production in men on testosterone, which otherwise suppresses it
Brings down undescended testicles in a proportion of boys treated

How it works

Binds the same receptor as luteinising hormone on Leydig cells in the testes, telling them to make testosterone directly. Because it acts below the pituitary, it works even when testosterone therapy has shut the pituitary's own signal off.

Binds a receptor on the cell surface and signals inward

Where it acts

Pituitary gland

The library groups this compound under Hormonal. The diagram shows that target, not every tissue it reaches.

Illustrated

A clinical histology-inspired cross-section of placental villi with fine capillaries in their centres, neutral tissue anatomy.

AI-generated subject illustration; not a depiction of the compound or evidence of its effects.

Why people take it

Fertility and ovulationTesticular function on TRTTestosterone productionPreserving sperm countPost-cycle recovery

Reasons people seek it out — not a list of proven effects.

In practice Off-label

Low doses two or three times a week alongside testosterone therapy to keep the testes working and preserve fertility
Used to restart the hormonal axis after coming off testosterone or anabolic steroids, often with an estrogen blocker
Prescribed by many TRT clinics as standard practice despite being off-label for it

Reported real-world use, not evidence and not a recommendation.

Dosing

What was tested Evidence

250–500 IU every other dayUp to 12 weeksMen on testosterone therapy, controlled study→ Intratesticular testosterone preserved near baseline
5,000–10,000 IU, single doseSingle injectionOvulation induction in fertility treatment→ Triggers ovulation roughly 36 hours later

What people report using Not evidence

250–500 IU twice weekly is the common figure alongside testosterone therapy
Higher doses used in restart protocols, tapering over several weeks

The fertility doses are from approved labelling. The TRT-adjacent doses come from clinical practice and small studies, not from approved indications.

Reported for reference, not as instruction. Nothing here is a recommendation to take anything, and most of these compounds are not approved for human use.

Status: FDA-approved as a prescription medicine for infertility and undescended testicles. Widely used off-label on testosterone therapy.

Route: Subcutaneous or intramuscular injection
Sequence: Glycoprotein hormone, two subunits of 92 and 145 amino acids
Molecular weight: ~36,700 g/mol
Available as: 5,000 IU, 10,000 IU

Search PubMed for HCG → We link a live search rather than a fixed citation list, so it stays current and nothing here is a reference we have not checked.

Educational information only. Nothing here is medical advice, a dosing protocol, or a recommendation to use any compound. Most entries describe substances not approved for human use. Talk to a licensed clinician before acting on anything you read here. How to read these entries.