Hormones & Fertility
Gonadorelin
Synthetic GnRH · Factrel
What it is
Gonadorelin is synthetic GnRH (gonadotropin-releasing hormone) — the natural pituitary signal that triggers LH and FSH release. Used clinically as a diagnostic agent for HPG axis function and increasingly added to TRT protocols as an HCG alternative.
How it works
Mimics natural GnRH pulses to stimulate LH and FSH release from the pituitary. This drives testicular function (LH → testosterone) and spermatogenesis (FSH). Half-life is very short (~10 minutes), requiring frequent dosing for sustained effect.
Benefits
- Maintains testicular function and size on TRT
- Preserves fertility on TRT
- Acts upstream of HCG (so doesn't downregulate Leydig cells the same way)
- FDA-approved (unlike most peptides on this list)
Timeline
- Hours
- LH/FSH pulse within hours of injection.
- Week 1–2
- Testicular size maintenance/restoration.
- Month 1–3
- Fertility preservation effects.
Dosing & titration
TRT companion100–200 mcg subQ, 2–3x weekly (or daily for some protocols)
Continuous protocol100 mcg every other day
When to titrate upSome debate around effective dose due to short half-life. Consider Kisspeptin or HCG if no testicular response.
Side effects & risks
- Generally well tolerated
- Mild injection site reactions
- Headache (rare)
- Some debate about whether typical dosing is sufficient given short half-life
Short half-life is a real consideration. Many users find HCG more effective for testicular preservation despite Gonadorelin's "purer" upstream action.
Typical price
$60–$120/moFrom a 503A compounding pharmacy.
Studies
- Search PubMed for gonadorelin — PubMed searchLive PubMed search
Educational reference only. Not medical advice.