Peptides for male fertility have one clear success: hCG, an FDA-approved peptide hormone, restores sperm production in most men whose infertility comes from low pituitary hormone signals. In a 2025 meta-analysis of 41 studies and 1,673 men, 78% produced sperm after a median 18 months of gonadotropin treatment, with better results when hCG was paired with FSH.[1] Kisspeptin and gonadorelin injections, often promoted online, have not been shown to improve sperm counts or pregnancy rates.[11]
This page reviews the evidence for each. For related topics, see our sexual health peptides hub.
Bottom line
| Peptide | How it works | Best evidence for fertility | Status |
|---|---|---|---|
| hCG | Acts like LH, telling the testes to make testosterone | Meta-analysis of 41 studies in hypogonadotropic hypogonadism[1] | FDA-approved for this use[2] |
| hMG / FSH | Supplies FSH, which drives sperm production | Improves results when added to hCG[1] | Approved products; male use off-label in US |
| Gonadorelin (GnRH) | Triggers the pituitary to release LH and FSH | Works by pump in congenital hypogonadism[6] | No approved US product; compounded |
| Kisspeptin-10 | Triggers the brain’s GnRH release | Raises hormones short-term; no sperm data[10] | Experimental |
How male fertility hormones work
Sperm production depends on a chain of signals. The brain’s hypothalamus releases kisspeptin, which triggers GnRH. GnRH tells the pituitary gland to release LH and FSH. LH drives testosterone production inside the testes, and FSH plus that local testosterone drive sperm production.
Each peptide on this page acts at a different link in that chain. They help most when the problem is a missing signal, not when the testes themselves are damaged.
hCG: the proven option
Who it helps. hCG is FDA-approved for selected cases of hypogonadotropic hypogonadism in men, meaning low testosterone caused by a pituitary or hypothalamic problem.[2] In these men, the testes are usually healthy but aren’t getting the signal to work.
The key study. A 2025 meta-analysis from Australia pooled 41 studies of 1,673 men, mean age 25. After a median 18 months of treatment:[1]
- 78% had sperm in the ejaculate.
- 55% reached more than 1 million sperm per mL, and 15% exceeded 20 million.
- Combined hCG and FSH beat hCG alone.
- Men with congenital (born-with) hypogonadism did less well than men who developed pituitary problems later.
Protecting fertility on testosterone therapy. Testosterone therapy suppresses LH and FSH, which can stop sperm production, so the Endocrine Society advises against it for men planning fertility soon.[3] Some clinicians add low-dose hCG:
- In a randomized study of healthy men whose hormones were suppressed with testosterone, low-dose hCG kept testosterone levels inside the testes near normal.[4]
- In a retrospective review of 26 men on testosterone plus 500 IU hCG every other day, none became azoospermic over about a year, and 9 contributed to a pregnancy.[5]
This use is off-label and rests on small studies. Since March 2020, hCG has been regulated as a biologic, which ended most compounding of it.[12]
Gonadorelin and pulsatile GnRH
GnRH must arrive in pulses to work. Given as a steady dose, it shuts the system down instead.
By pump, it works. In a landmark 1982 study, low-dose GnRH pulses delivered by a portable pump induced puberty in men with GnRH deficiency.[7] A 2021 meta-analysis of 7 studies (420 men with congenital hypogonadotropic hypogonadism) found pump GnRH produced larger testes and sperm about 5 months sooner than gonadotropin injections, though rates of sperm appearance were similar.[6]
As occasional injections, it’s unproven. Gonadorelin disappears from the blood within minutes.[8] Some clinics now prescribe compounded gonadorelin once daily or a few times a week alongside testosterone. A 2026 review found direct evidence for restoring sperm production after testosterone suppression remains limited.[11] See our peptides vs TRT comparison for more.
Kisspeptin: promising but early
Short-term hormone effects. In healthy men, an IV dose of kisspeptin-10 tripled LH within 30 minutes, and a 22.5-hour infusion raised testosterone from about 16.6 to 24.0 nmol/L.[9]
Longer use (2026). In a small Imperial College London study, daily 8-hour infusions under the skin kept LH, FSH and testosterone elevated for 12 days. Continuous infusion, by contrast, lost its effect on LH and FSH within 5 days.[10]
No study has tested kisspeptin’s effect on sperm counts or pregnancy. FDA lists kisspeptin-10 among compounding substances that may pose significant safety risks.[13]
Choosing between them: questions for your doctor
The right option depends on why sperm production is low. Questions worth raising with a specialist:
- Are my LH and FSH low, normal or high? Low levels point to a signaling problem that hCG, FSH or pump GnRH can address.[1] High levels usually mean the testes themselves are struggling, and these hormones are unlikely to help.
- Am I on testosterone, or planning to start? If so, ask about fertility protection or stopping before trying to conceive.[3]
- Would FSH, such as hMG, add benefit? Combined treatment produced more sperm than hCG alone in the meta-analysis.[1]
- Is a compounded product being suggested? Ask what evidence supports the specific dose and schedule, particularly for gonadorelin or kisspeptin-10.[11]
Established vs preliminary
Established:
- hCG plus FSH can start sperm production in most men with pituitary-related hypogonadism.[1]
- Testosterone therapy suppresses fertility.[3]
Preliminary:
- Whether hCG reliably protects fertility on long-term testosterone therapy.
- Whether intermittent gonadorelin injections do anything useful.
- Whether kisspeptin can treat infertility.
Limitations
- Most men with infertility don’t have low pituitary hormones. For them, these peptides aren’t a proven fix.
- Small, uncontrolled studies dominate the TRT-related research.[5]
- Long timelines. Sperm take about 2 to 3 months to develop, and treatment often runs 18 months or more.[1]
What’s next
Researchers are exploring kisspeptin-based treatments and other brain-signaling approaches for men with suppressed hormones, but a 2026 review notes that long-term efficacy and safety are unanswered.[11]
If you’re trying to conceive, a reproductive urologist or endocrinologist can test your hormones and identify whether these treatments fit. Related reading: PT-141 vs Viagra for sexual function and peptides for prostate health.
