What Is Gonadorelin? Dosage, Half-Life & How to Track It
Also known as: Gonadorelin Acetate · Factrel · Lutrepulse · GnRH
Gonadorelin is a synthetic version of gonadotropin-releasing hormone (GnRH), the hypothalamic signal that tells the pituitary to release LH and FSH. Run as small subcutaneous micro-doses — commonly 50–150 mcg, 2–3 times a week — it’s used to keep the pituitary end of the HPG axis active during TRT rather than letting it go fully quiet. Its native half-life is only around 2–4 minutes, which is exactly why it’s dosed as intermittent pulses instead of continuously. Educational only.
What gonadorelin is and how it works
Gonadorelin is bioidentical (or very close to identical) synthetic GnRH — the decapeptide the hypothalamus releases in pulses to tell the pituitary to secrete LH and FSH. It acts one level higher in the axis than hCG: hCG mimics LH and works directly on the testes, while gonadorelin works on the pituitary itself, prompting it to keep making its own LH and FSH.
That distinction matters for what it’s used for. On TRT, exogenous testosterone suppresses the hypothalamus and pituitary, not just the testes — gonadorelin is one way to keep that upstream signaling alive, which is the theoretical case for it over hCG alone, since hCG does nothing for the pituitary itself.
One counterintuitive wrinkle: GnRH only stimulates the axis when delivered in pulses. Continuous, non-pulsatile GnRH exposure actually desensitizes and shuts the pituitary down — the mechanism medical GnRH agonists exploit for hormone-suppression therapy. That is why gonadorelin protocols use small, spaced-out doses rather than one large one.
Typical dosing & reconstitution
A common maintenance approach is 50–150 mcg subcutaneously, 2–3 times a week on non-consecutive days, often starting at the low end and titrating up over the first few weeks. Some post-cycle or restart protocols use daily or every-other-day dosing for a short, defined window — generally capped around two weeks — rather than as an ongoing maintenance schedule.
Gonadorelin comes as a lyophilized powder:
| Vial | BAC water | Concentration | 1 unit ≈ |
|---|---|---|---|
| 2 mg | 2 mL | 1 mg/mL | 10 mcg |
At 1 mg/mL, a 100 mcg dose is 10 units on a U-100 insulin syringe. Because doses run small, a 30- or 50-unit syringe reads more precisely than a standard 100-unit one.
Half-life & what it means for frequency
Native GnRH clears in minutes — roughly 2–4 minutes — which is short even by peptide standards. That is by design: the pituitary is built to respond to brief pulses, not a sustained signal, so gonadorelin’s short half-life is what makes it capable of mimicking a natural GnRH pulse in the first place rather than working against it.
The practical upshot is that gonadorelin can’t build up between doses the way a longer peptide can — each injection is its own discrete pulse, which is also why the dosing schedule (2–3 times weekly, spaced out) matters more for this compound than the exact dose size.
What to track & common side effects
Reported side effects are typically mild — injection-site reactions, headache, or flushing shortly after a dose. Because it stimulates the same axis as hCG one level upstream, side effects that trace back to rising testosterone or estradiol (mood shifts, water retention) can show up the same way.
What’s worth tracking: each dose and day (the 2–3×/week rhythm is easy to lose track of against a daily testosterone-shot habit), and the same labs a TRT-plus-gonadorelin protocol is monitoring — testosterone, LH/FSH if your prescriber checks them, and estradiol.
How to track Gonadorelin in Stackeddd
Log each gonadorelin pulse next to your testosterone protocol so the 2–3×/week rhythm doesn’t get lost against a different injection schedule. The reconstitution math is worth locking in once — gonadorelin doses run small enough that a unit-measurement mistake matters more than it would with a larger-volume peptide.
Model it yourself · free, no account
Reconstitution Calculator
Model it yourself: enter your vial size and BAC water, and the Peptides tab returns concentration and exact units for any micro-dose — the same math built into the Stackeddd app.
Related compounds
Related reading: TRT Math: what mg/mL actually means · Peptide reconstitution math: how much BAC water to add
Frequently asked questions
What is gonadorelin used for?
It’s a synthetic form of GnRH used alongside TRT to keep the pituitary signaling LH and FSH — the upstream step exogenous testosterone otherwise suppresses. It’s also used in short pulsatile protocols for fertility support and TRT restarts.
What is the half-life of gonadorelin?
Only about 2–4 minutes. That short window is what lets it act as a discrete pulse the pituitary responds to, rather than a sustained signal — continuous GnRH exposure actually suppresses the pituitary instead of stimulating it.
How is gonadorelin different from hCG?
hCG mimics LH and acts directly on the testes; gonadorelin acts one step earlier, on the pituitary, prompting it to release its own LH and FSH. They target different points in the same axis, which is why some protocols use one, the other, or both.
How often is gonadorelin dosed?
A common maintenance schedule is 2–3 small subcutaneous doses a week on non-consecutive days. Some short-term restart or post-cycle protocols use daily or every-other-day dosing for a limited window instead.
This is educational information, not medical advice. Doses and protocols above reflect published references and community practice — protocol decisions belong with your prescribing physician. Generic names used throughout. How this reference is built & how the AI is tested →
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