Gonadorelin
FDA APPROVEDGnRH analog | Hormonal support and fertility
By the INFOPEPTIDOS editorial team · content based on scientific literature.
Updated: August 2026.
Key points
- What it is: analog of gonadotropin-releasing hormone (GnRH).
- Main use: hormonal support, fertility and testicular maintenance in TRT.
- Typical dose: 100–200 mcg, 2–3 times a week or every other day, subcutaneous.
- Key result: stimulates the pituitary to release LH and FSH, and these the testis.
- Common effects: mild injection-site reaction; hormonal changes.
- Comparison: an alternative to HCG for maintaining testicular function in TRT.
- Status: FDA-approved (diagnostic and therapeutic use).
Technical data: Molecular formula C55H75N17O13 · Molecular weight 1182.3 g/mol. Source: PubChem.
Overview
What is gonadorelin?
Gonadorelin is a synthetic analog of gonadotropin-releasing hormone (GnRH), the signal with which the hypothalamus starts the reproductive hormone axis. It is used mainly in testosterone therapy (TRT) support to maintain testicular function and size, and in fertility.
Key benefits
It keeps the body's own testosterone production and testicular function active during TRT, avoiding part of the associated atrophy. It is also used in assessing and stimulating the reproductive axis. It is an alternative to HCG.
Mechanism of action
It mimics GnRH and stimulates the pituitary to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH); these in turn act on the testis (or ovary) to produce sex hormones. Its action is pulsatile and short-lived.
Quick start guide
Dosing protocol
| Phase | Dose | Frequency | Duration |
|---|---|---|---|
| TRT support | 100–200 mcg | 2–3 times/week or every other day | Continuous with TRT |
Subcutaneous route. Dose and frequency depend on the goal (fertility, testicular maintenance). The regimen must be set by a healthcare professional.
Reconstitution: units in the syringe
Example with a 5 mg vial + 2 ml of bacteriostatic water → a 2.5 mg/ml solution. On a U-100 insulin syringe (100 units = 1 ml):
| Dose | Volume | Units (U-100) |
|---|---|---|
| 100 mcg | 0.04 ml | 4 U |
| 200 mcg | 0.08 ml | 8 U |
Is your vial or water different? Calculate the exact units below.
🧮 Calculate your exact syringe dose →⚠️ Who should NOT use it
- People with hormone-dependent tumors — consult first.
- Pregnancy or breastfeeding.
- Undiagnosed hormonal disorders — assess with the doctor.
- Always under the supervision of a healthcare professional.
What to expect
- Week 1-2: reactivation of the LH/FSH signal.
- Week 2-4: maintenance of testicular function and size.
- Week 4-8: stable hormonal support alongside TRT.
- Continuous use: keeps the axis active while administered.
- Side effects: mild injection reaction; hormonal changes.
- Most effective for: maintaining testicular function in TRT and fertility.
Side effects & safety
- Mild injection-site reaction.
- Hormonal changes (part of the intended effect).
- Occasional headache or nausea.
- Transient flushing or hot flashes.
- Breast tenderness in some cases.
- Allergic reaction: rash, itching or swelling.
- Severe abdominal or pelvic pain.
- Vision changes or severe headache.
- Any striking, persistent symptom.
- If you are pregnant or planning a pregnancy.
Frequently asked questions
What is gonadorelin?
It is a GnRH analog that stimulates the pituitary to release LH and FSH, activating the reproductive axis.
What is it used for in TRT?
To maintain the body's own testosterone production and avoid testicular atrophy during therapy.
What is the gonadorelin dose?
Typically 100-200 mcg, 2-3 times a week or every other day. The regimen is set by a professional.
Is it an alternative to HCG?
Yes; it is used as an alternative to HCG to maintain testicular function in TRT.
What are the side effects?
Mild injection reaction and hormonal changes; occasional headache or flushing.
Is gonadorelin approved?
Yes; it is FDA-approved for diagnostic and therapeutic uses.
Research areas
- Hormonal support
- Fertility
- Testicular maintenance (TRT)
- Reproductive axis
- Hormonal health
Related peptides
- Kisspeptin-10 — Activates the reproductive axis upstream of GnRH.
- PT-141 — Melanocortin agonist for sexual function.
- Sermorelin — GHRH analog of the GH axis.
Related articles
Related topics
- Gonadorelin and TRT
- Gonadorelin dose
- Gonadorelin vs HCG
- Gonadorelin fertility
- Gonadorelin testicles
- Gonadorelin side effects
Summary
What it is: GnRH analog.
How it is researched: Subcutaneous, 100-200 mcg, 2-3 times/week.
Key features: Maintains testicular function in TRT. FDA-approved.
Related peptides: Kisspeptin-10, PT-141 and Sermorelin.
References
- Hashimoto T et al. (1981). Gonadorelin and erythropoiesis. Arch Intern Med. PubMed
- Torrini F et al. (2023). Advances and perspectives in the analytical technology for small peptide hormones analysis: A glimpse to gonadorelin. J Pharm Biomed Anal. PubMed · DOI
- Bouchard P (2005). [Gonadorelin antagonists: present and future ]. Rev Prat. PubMed
- (1983). Gonadorelin--synthetic LH-RH. Med Lett Drugs Ther. PubMed
Studies compiled from PubMed for informational purposes; many are preclinical or research-stage and do not constitute medical advice.