Peptide Schedule
Gonadorelin10 residuesQHWSYGLRPGEach bubble = one amino acid. Size = residue mass. Color = chemical class.Gonadorelin
Benefits
About Gonadorelin
Gonadorelin is a synthetic version of gonadotropin-releasing hormone (GnRH), the 10-amino-acid peptide your hypothalamus naturally pulses every 60-120 minutes to drive testosterone and fertility. It was FDA-approved in 1978 under the brand name Factrel for diagnostic testing of pituitary gonadotroph function. Today it's widely used off-label alongside TRT to preserve testicular function and fertility, and in post-cycle therapy to restart the HPG axis after anabolic steroid use. Its extremely short half-life means dosing protocol matters more than dose size — pulsatile subcutaneous injections maintain receptor sensitivity, while continuous exposure shuts the system down.
Who Should Consider Gonadorelin
- Men on TRT wanting to maintain fertility and testicular size
- Athletes in post-cycle therapy after anabolic steroid use
- Men with secondary hypogonadism seeking natural testosterone stimulation
- Clinicians performing pituitary function diagnostics
How Gonadorelin Works
Gonadorelin binds to GnRH receptors (GnRHR) on gonadotroph cells in the anterior pituitary. This triggers a Gq/11-coupled signaling cascade that activates phospholipase C, increasing intracellular calcium and releasing LH and FSH into the bloodstream. LH acts on Leydig cells in the testes to produce testosterone, while FSH drives spermatogenesis through Sertoli cells. The key nuance: GnRH receptors require pulsatile stimulation to stay responsive. Constant exposure causes receptor internalization and downregulation — which is actually how GnRH agonists like leuprolide work to suppress testosterone in prostate cancer.
What to Expect
Acute LH spike measurable within 15-30 minutes. No subjective effects yet.
LH and FSH levels stabilizing with consistent pulsatile dosing.
Testosterone levels start rising if pituitary-gonadal axis is intact.
Full effect on testosterone, testicular volume, and spermatogenesis measurable on labs.
Dosing Protocol
| Level | Dose / Injection | Frequency |
|---|---|---|
| Beginner | 100mcg | 2x/week |
| Moderate | 200mcg | 2x/week |
| Aggressive | 200mcg | 3x/week |
Note: Synthetic GnRH. FDA-approved as Factrel for pituitary diagnostic testing. Pulsatile dosing is critical — continuous exposure desensitizes GnRH receptors and suppresses LH/FSH. Space injections at least 2 days apart.
How to Inject Gonadorelin
Inject subcutaneously into abdominal fat or thigh. Rotate sites. Dose 2-3 times per week with at least 48 hours between injections to preserve pulsatile receptor sensitivity. Morning dosing may better align with natural GnRH pulsatility. Don't exceed 200mcg per injection.
Cycling Protocol
When used alongside TRT, many clinicians run continuously at 2x/week. For PCT, a typical course is 4-8 weeks.
Pharmacokinetics
Source: Factrel FDA label; SC terminal t½ ~20-40 min (IV t½ 2-10 min, but administration is SC)
Loading the interactive decay curve.
Side Effects
Generally well-tolerated. Headache, nausea, and mild injection site reactions are most common. Flushing and lightheadedness can occur shortly after injection. Continuous or excessive dosing can paradoxically suppress LH/FSH through receptor desensitization — the opposite of the intended effect.
Contraindications
- Hormone-dependent tumors (breast, prostate)
- Pituitary apoplexy or known pituitary adenoma
- Pregnancy
- Primary hypogonadism — pituitary stimulation won't help if testes can't respond
Drug Interactions
- Androgens, estrogens, progestins — may blunt therapeutic effect
- Oral contraceptives and digoxin — can suppress gonadotropin response
- Phenothiazines and dopamine antagonists — may blunt LH/FSH response
Storage & Stability
Molecular Profile
Related Peptides
References
- Factrel (gonadorelin HCl) FDA LabelFDA Label
- GnRH agonists: gonadorelin, leuprolide and nafarelinPubMed 1835275