Carl read the papersWhat it actually is
Gonadorelin is synthetic gonadotropin-releasing hormone; it signals the pituitary to release LH and FSH.
Unlike HCG (which only mimics LH), it drives both — so it supports testosterone AND fertility (FSH), but its ultra-short half-life means frequent dosing.
How it’s thought to work
- Pituitary signalling — releases LH + FSH (both, vs HCG’s LH-only mimicry).
- Testicular support — LH → testosterone; FSH → spermatogenesis.
- Ultra-short half-life — a few minutes → mimics natural pulses but needs frequent dosing.
- Keeps the axis active — preserves the HPTA signal chain vs bypassing it.
What the research says
FDA-approved in the past as Factrel (1982, diagnostic use) and Lutrepulse (1989, pulse pump), but Drugs@FDA lists both as discontinued in the US. Pulse-pump GnRH is still used for hypogonadotropic hypogonadism in some countries, such as China. TRT-companion micro-dosing is common but off-label; needs an intact pituitary to work.
- Testicular maintenance on TRT (size/function): user reports only, we found no trials in men on TRT.
- Fertility support (drives FSH).
- HPTA restart aid (reported, untested).
Watch: Gonadorelin explained
Video by R&ACT on YouTube. Not affiliated with Peptide Carl and not an endorsement — included because a second explanation of the same mechanism is often what makes it click.
Reported protocols
These are the doses the peptide community actually reports running (Reddit & forums), alongside published research — logged for education, not as a recommendation to use.
| Parameter | Commonly reported range |
|---|---|
| Community dose | ~100 mcg per injection (range 100–200) |
| Frequency | Daily, often split 2×/day (ultra-short half-life) |
| Route | SubQ |
| Cycle | Continuous alongside TRT (ongoing, not cycled) |
| Community tip | Its few-minute half-life is the catch — dose it too infrequently and it does little |
Common use cases
| Goal | Community protocol notes |
|---|---|
| Testicular maintenance on TRT | ~100 mcg daily/2×day subQ, ongoing |
| Fertility (FSH support) | the reason some pick it over HCG |
| HPTA restart aid | pulsatile dosing |
Mixing it (reconstitution)
Freeze-dried peptides must be reconstituted with bacteriostatic water before they can be measured. Carl’s calculator turns “mg in the vial + ml of water + target dose” into “units on the syringe” — and tells you how long the vial lasts.
→ Open the Reconstitution Calculator
Injection & handling
SubQ, ~100 mcg, daily and often split twice-daily because of the few-minute half-life (many dose before each testosterone shot). Refrigerate reconstituted.
Stacks it appears in
- TRT companion — Gonadorelin alongside testosterone — testicular/fertility maintenance.
Sources
- Drugs@FDA: Factrel (gonadorelin HCl), NDA 018123
- Drugs@FDA: Lutrepulse (gonadorelin acetate), NDA 019687
- GnRH clearance and half-life in normal subjects, JCEM 1977 (PMID 320223)
- LHRH half-life in women, Acta Endocrinol 1981 (PMID 7006293)
- Continuous vs intermittent GnRH, Science 1978 (PMID 100883)
- Pulsatile GnRH induces puberty in men, NEJM 1982 (PMID 6813732)
- Gonadorelin pump vs hCG/hMG in CHH men, Am J Mens Health 2019 (PMID 30569789)
- Peptide strategies for TRT-induced suppression review, Front Reprod Health 2026 (PMID 42666625)
- hCG high dose vs divided doses, JCEM 1984 (PMID 6693540)
