HCG stimulates the testes to produce testosterone and sperm, because it acts on the same receptor as luteinising hormone, or LH. That is why it is an approved drug for men with a deficiency of pituitary hormones. In a 2025 meta-analysis of 1673 patients, gonadotropin treatment restored sperm production in 78 percent of them. Below you will find how HCG acts on the testes, what studies in men showed and what is in a 5000 IU vial.
How does HCG work in men?
HCG, human chorionic gonadotropin, binds to the LH receptor on the Leydig cells in the testes. Leydig cells are responsible for producing testosterone. In a healthy body the signal for this comes from the pituitary, which releases LH. HCG replaces that signal, so the testes produce testosterone even when the pituitary is silent.
Testosterone made in the testes has a second task that matters more for fertility. Its concentration inside the testes is needed for sperm to mature. Testosterone given from outside does not provide this, because it suppresses the pituitary and lowers production in the testes themselves. HCG keeps that production going from within, and this is the basis of its role in treating male infertility.
What is HCG approved for in men?
The US label for chorionic gonadotropin lists two indications in men. The first is prepubertal cryptorchidism, when a testis has not descended into the scrotum and the cause is not an anatomical obstruction. The second is selected cases of hypogonadotropic hypogonadism, a testosterone deficiency caused by pituitary failure. A third indication concerns women and consists of inducing ovulation.
The same label contains a sentence worth knowing. It states in capital letters that HCG is not an effective aid in treating obesity. There is no evidence that it increases weight loss beyond the effect of diet alone. Contraindications are precocious puberty, prostate cancer or another androgen-dependent tumour, and allergy to HCG. A general description of the molecule is in the guide on HCG and chorionic gonadotropin.
Does HCG restore sperm production?
Yes, in most men with gonadotropin deficiency, treatment restores sperm production. A meta-analysis of 41 studies with 1673 patients was published in Clinical Endocrinology in 2025. The average age of participants was 25. After a median of 18 months of treatment, the mean sperm concentration was 11.6 million per millilitre of semen.
| Sperm concentration after treatment | Share of patients |
|---|---|
| above 0 (sperm present) | 78 percent |
| above 1 million per ml | 55 percent |
| above 5 million per ml | 36 percent |
| above 10 million per ml | 24 percent |
| above 20 million per ml | 15 percent |
Combining HCG with FSH, the second pituitary hormone, gave more sperm than HCG alone. The rise in testosterone and in testicular volume was similar with both treatments. The authors stress that only a smaller share of patients reached the concentrations typically needed for natural conception.
How quickly does sperm appear?
In a Korean study from 2025, sperm appeared in 82 percent of men, after a median of 7.5 months of treatment. The paper was published in the World Journal of Men's Health. It included 65 men with gonadotropin deficiency since childhood, and the full analysis covered 50 of them. Treatment started with HCG three times a week for four weeks, after which recombinant FSH was added.
After HCG alone, median testosterone rose from 0.10 to 3.16 ng/ml. Median testicular volume increased during treatment from 4.0 to 9.0 ml. The only factor that predicted success was a larger testicular volume at the start. Of six couples trying for a child, four achieved a pregnancy.
Does HCG protect fertility during testosterone therapy?
In a 2013 study, none of 26 men combining testosterone with a low dose of HCG lost sperm from their semen. The paper was published in the Journal of Urology. The authors note that testosterone therapy alone leads to an absence of sperm in about 40 percent of patients, because it suppresses the pituitary. Participants received testosterone as a gel or injections, plus 500 IU of HCG into the muscle every other day.
After an average of 6.2 months of follow-up, testosterone rose from 207 to 1056 ng/dl. Semen parameters did not change over more than a year of follow-up. During that time the partners of 9 of the 26 men became pregnant. This is a retrospective study without a control group, so its result is treated as a pointer, not final proof.
Can HCG be given under the skin instead of into the muscle?
Yes, in a 1991 study HCG given under the skin stimulated testosterone production just as well as HCG given into the muscle. The paper was published in Fertility and Sterility. It included 24 healthy men with an average age of 22.7, randomly split into two groups. Each received a single dose of 5000 IU of HCG, either under the skin or into the muscle.
After subcutaneous injection, the peak HCG level in the blood came later and the half-life was longer. The response of testosterone, LH and FSH was, however, identical in both groups. Measurements were taken for 144 hours after the injection. The authors judged subcutaneous injection equally effective at stimulating hormone production.
| Study | Who | Result |
|---|---|---|
| Saal et al., 1991 | 24 healthy men | 5000 IU under the skin and into the muscle gave the same testosterone response |
| Hsieh et al., 2013 | 26 men on testosterone | 500 IU every other day, none lost sperm |
| Muir et al., 2025 | 1673 patients in 41 studies | sperm appeared in 78 percent |
| Cho et al., 2025 | 50 men in the analysis | sperm in 82 percent after a median of 7.5 months |
What was measured in studies of HCG in men?
In all the studies described, the outcome was assessed with three groups of measurements: hormones in the blood, semen and testicular volume. Each tells you something different. Testosterone shows whether the testes responded to the signal. Semen shows whether sperm production has started. Testicular volume grows more slowly and reflects the rebuilding of the tissue that makes the sperm.
- Total and free testosterone. In the 2013 study, free testosterone rose from 8.1 to 20.4 pg/ml.
- LH and FSH. In the 1991 study they were measured together with testosterone for 144 hours after a single dose.
- Semen. Volume, sperm concentration and motility were assessed. Before testosterone treatment the mean concentration was 35.2 million per ml and motility 49 percent.
- Testicular volume. In the Korean study it was measured every three months, and it was the best predictor of success.
Blood tests show an effect within days, while semen and testicular volume show it only after months. The median time until sperm appeared was 7.5 months. More on how to measure results in peptide research is in the guide on how to measure peptide results.
How does HCG in a vial differ from the drug?
HCG in the shop contains the same substance as chorionic gonadotropin drugs, but it is not a drug. Chorionic gonadotropin drugs, such as Ovitrelle in the EU, are dispensed only on prescription, and treatment is run by a doctor. A vial in the shop is material for laboratory research, without approval and without drug quality control. The legal status of such substances is described in the guide on the legal status of peptides.
The content of HCG is given in international units, not milligrams, because what is measured is its biological activity. Where this difference comes from and how to read it is explained in the guide on IU vs milligrams.
Where to buy HCG and how much does it cost?
In the shop, HCG comes in 5000 IU vials from two brands, each for 25 EUR. HCG 5000 IU Genheal is in stock. HCG 5000 IU Bio-Peptide is available on backorder. A description of the molecule and both versions are on the HCG page. Before use the powder is dissolved following the guide on how to reconstitute peptides.
Frequently asked questions
Does HCG raise testosterone in men?
Yes. HCG acts on the LH receptor in Leydig cells and stimulates the testes to produce testosterone. In a 2025 study, median testosterone rose after HCG from 0.10 to 3.16 ng/ml.
Does HCG help with male infertility?
In men with gonadotropin deficiency, yes. In a meta-analysis of 41 studies, treatment restored sperm production in 78 percent of patients, better in combination with FSH.
Does HCG protect fertility during testosterone therapy?
In a 2013 study, none of 26 men taking testosterone with 500 IU of HCG every other day lost sperm from their semen.
Can HCG be given subcutaneously?
In a 1991 study, 5000 IU of HCG under the skin gave the same testosterone, LH and FSH response as an injection into the muscle.
Does HCG help with weight loss?
No. The US HCG label states that there is no evidence it increases weight loss beyond the effect of diet alone.
This is information about published research, not medical advice. The choice of treatment belongs to a doctor.
Sources
- Muir CA, Zhang T, Jayadev V et al. Efficacy of Gonadotropin Treatment for Induction of Spermatogenesis in Men With Pathologic Gonadotropin Deficiency: A Meta-Analysis. Clinical Endocrinology, 2025, 102(2): 167-177. https://doi.org/10.1111/cen.15151
- Cho MC, Lee H, Kim SW. Induction of Spermatogenesis and Its Predictors in Men with Prepubertal-Onset Hypogonadotropic Hypogonadism Undergoing Gonadotropin Therapy. World Journal of Men's Health, 2025, 43(4): 992-1001. https://doi.org/10.5534/wjmh.250117
- Hsieh TC, Pastuszak AW, Hwang K, Lipshultz LI. Concomitant intramuscular human chorionic gonadotropin preserves spermatogenesis in men undergoing testosterone replacement therapy. Journal of Urology, 2013, 189(2): 647-650. https://doi.org/10.1016/j.juro.2012.09.043
- Saal W, Glowania HJ, Hengst W, Happ J. Pharmacodynamics and pharmacokinetics after subcutaneous and intramuscular injection of human chorionic gonadotropin. Fertility and Sterility, 1991, 56(2): 225-229. https://pubmed.ncbi.nlm.nih.gov/1712735/
- European Medicines Agency. Ovitrelle (choriogonadotropin alfa), European public assessment report. https://www.ema.europa.eu/en/medicines/human/EPAR/ovitrelle
- Chorionic Gonadotropin for injection, prescribing information, DailyMed, 2025. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=f93b2baa-03ac-4650-b35a-20b818d712d6