In plain English
HCG is the hormone that pregnancy tests detect. In men, it acts like LH, telling the testicles to make testosterone and sperm. It is an FDA-approved medicine for certain fertility problems and is widely used alongside testosterone therapy.
What it's used for
- Ovulation induction in women (approved)
- Low testosterone from pituitary causes in men (approved)
- Undescended testicles in boys (approved)
- Keeping testicular size and fertility on TRT (common practice)
Benefits
In human studies, HCG raised testosterone and supported sperm production in men with low LH, and kept testicular testosterone up in men on TRT.
- Maintains testicle size and function
- Supports fertility
- Raises natural testosterone
How it works
In simple terms: HCG stands in for LH, the brain’s “make testosterone” signal.
It binds the LH receptor on Leydig cells in the testicles (and on the ovary), driving testosterone or progesterone production. It does not pass through the brain’s control system, so it works even when the pituitary is suppressed.
Development history
- 1920s: Discovered in the urine of pregnant women.
- 1970s: Approved for fertility uses in the US.
- Today: Brands include Pregnyl and Novarel; a recombinant form (Ovidrel) is also approved.
Typical protocols
Prescribed doses follow the prescribing label or your doctor. TRT doses are what clinics and users commonly report.
| Use | Dose | Frequency |
|---|---|---|
| On TRT | 250–500 IU | 2–3 times a week |
| Low testosterone (label) | Ranges such as 1,000–2,000 IU | 2–3 times a week |
Cycling
On TRT it is often used continuously alongside testosterone.
Administration options
Subcutaneous or intramuscular injection.
Reconstitution and dosing calculator
HCG is measured in IU. To use the calculator, enter IU as if they were mcg: a 10,000 IU vial is entered as 10 mg, and a 500 IU dose as 500 mcg. A 10,000 IU vial with 5 mL of water gives 2,000 IU per mL, so 500 IU is 25 units.
Draw your syringe to
– units
- Volume to draw
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- Concentration
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- Each unit holds
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- Doses per vial
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Show the math
This tool does arithmetic only. It does not choose a dose or confirm that any substance is right for you. Double-check every result against your syringe and your clinician’s instructions.
Side effects and safety
- Higher estrogen levels, which can cause water retention, moodiness or breast tenderness.
- Acne and injection-site reactions.
- In women: risk of ovarian hyperstimulation.
- Prohibited for men in competitive sport (WADA).
Common stacks
- Testosterone: the standard pairing on TRT.
- Gonadorelin: an alternative approach.
Storage
Before mixing: room temperature or refrigerator (check the label). After mixing: refrigerate and use within about 30–60 days.
Compare with
- Gonadorelin: acts higher up, on the pituitary, and is short-acting.
- Kisspeptin: acts higher still, on the brain.
Frequently asked questions
HCG or gonadorelin on TRT?
HCG acts directly on the testicles and is very reliable. Gonadorelin works through the pituitary; users report mixed results.
References
- Coviello AD, et al. Low-dose human chorionic gonadotropin maintains intratesticular testosterone in normal men with testosterone-induced gonadotropin suppression. J Clin Endocrinol Metab. 2005;90(5):2595-2602.
- Pregnyl (chorionic gonadotropin) prescribing information. Organon.