Gonadorelin
Also known as · GnRH · LHRH · Factrel (animal) · Lutrepulse (withdrawn)
- EvidenceApproved
- CategoryGonadotropin
- RoutesubQ / IV pump
- Half-life2–4 min
01 / Dosing schedule
Cited dosing
Gonadorelin has no current US-marketed human FDA prescribing information (Factrel is now an animal-drug label; Lutrepulse was discontinued). Historic human labels used single-dose diagnostic testing and continuous-pulse pump infusion. The popular subcutaneous TRT-adjunct schedule is compounding-pharmacy practice, not FDA-approved.
Pulsatile pump — fertility induction in men with hypogonadotropic hypogonadism
| Phase | Dose & frequency |
|---|---|
| Pump dose | 5–20 mcg subQ every 60–120 minutes |
| Duration | Continuous, months (until spermatogenesis) |
| Route | Subcutaneous via portable infusion pump |
| Median time to first sperm | ~6 months |
Compounding-pharmacy TRT-adjunct schedule (not FDA-approved)
| Phase | Dose & frequency |
|---|---|
| Conservative | 100 mcg subQ 2–3x weekly |
| Common telehealth default | 100–200 mcg subQ twice daily |
| Route | Subcutaneous, abdomen or thigh |
| Evidence | No RCT vs hCG; each dose fires a single LH pulse then clears |
Source · See TRT-adjunct evidence review (mechanism + trial gap) ↗
Source indication · Historically: diagnostic assessment of gonadotropin reserve; fertility induction via pulsatile pump. Not FDA-approved for TRT adjunct.
- Injection frequency
- Pulsatile pump: every 60–120 min. Bolus schedules: 2–3x weekly to twice daily.
- Injection sites
- Abdomen or thigh for subQ boluses. Pump infusion typically subQ.
02 / Reconstitution
Reconstitution reference
Research-grade gonadorelin typically ships as a 10 mg lyophilized vial. A common prep is 10 mg with 10 mL bacteriostatic water = 1 mg/mL (1000 mcg/mL). At that concentration, a 100 mcg dose is 0.1 mL = 10 units on a U‑100 syringe.
03 / Overview
Protocol overview
Gonadorelin is synthetic gonadotropin-releasing hormone (GnRH, LHRH). It stimulates the anterior pituitary to release LH and FSH, which in turn drive gonadal steroid and gamete production.
Historic FDA-approved human indications used gonadorelin as a diagnostic agent and via portable pulsatile pump for fertility induction. Both human products (Factrel injection, Lutrepulse) have been withdrawn or reclassified.
The 2–4 minute plasma half-life is the central mechanistic issue for TRT-adjunct use. A single subcutaneous bolus fires one LH pulse, then clears — unlike hCG, which supplies continuous LH-receptor activity for days.
No randomized controlled trial compares twice-daily subcutaneous gonadorelin to hCG on TRT for testicular volume, intratesticular testosterone, or sperm-count endpoints. The popular telehealth schedule sits between two published literatures it does not formally belong to.
04 / References