Gonadorelin

Hormones & fertility Research compound (not approved for human use)

Synthetic GnRH decapeptide · also known as GnRH, Gonadotropin-releasing hormone, Factrel

For reference only — not medical advice. Figures are commonly reported values compiled from published sources and may be wrong or out of date. Many compounds listed are not approved for human use. Talk to a licensed clinician before using any compound.

Gonadorelin was formerly marketed in the US as a diagnostic agent for pituitary function, and the same molecule given in pulses by pump has been used to treat gonadotropin deficiency. Reference charts describe periodic, low-dose schedules aimed at stimulating LH and FSH release, for example in men whose testes are suppressed during testosterone therapy.

Commonly reported dosing (2 mg vial)

Reconstituted with 2 mL → 1 mg/mL.

Phase	Dose	Volume	U-100 units
Starting	50 mcg	0.05 mL	5
Standard	100 mcg	0.1 mL	10
Higher	150 mcg	0.15 mL	15
Short burst (reported)	200 mcg	0.2 mL	20

Frequency: Commonly reported 2-3 times weekly on non-consecutive days · Half-life: Very short (minutes)

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Commonly reported reconstitution steps

Vials are usually brought to room temperature (about 15-20 minutes) first.
2 mL of bacteriostatic water is added slowly down the inside wall of the 2 mg vial.
The vial is swirled gently until clear, not shaken.
This gives 1 mg/mL. Mixed vials are typically labeled with the date and refrigerated.

Storage

Before mixing: Lyophilized research vials are commonly stored frozen (around -20 °C), dry and protected from light.

After mixing: Reconstituted solution is commonly kept refrigerated (2-8 °C) and protected from light, with repeated freeze-thaw cycles avoided.

How it works

Gonadorelin binds GnRH receptors on pituitary gonadotrophs. Pulsatile exposure triggers LH and FSH release, whereas continuous exposure desensitizes the receptor and lowers gonadotropin output, which is the basis of GnRH agonist drugs.

Researched for

Pulsatile pump therapy studied in congenital hypogonadotropic hypogonadism for inducing puberty and spermatogenesis.
Historically used as a diagnostic test of pituitary gonadotropin reserve.
Periodic subcutaneous schedules appear in reference charts; controlled human data for those schedules are limited.

Notes

Human-use gonadorelin products are not currently marketed in the US under an approved label (DailyMed lists veterinary products), so this entry is classed as research-only.
Published pump studies used small pulses (on the order of 10 mcg) every 90 minutes, which differs substantially from intermittent injection schedules.
Because of its minutes-long half-life, effects after a single administration are brief.

Sources

Last reviewed 2026-10-05.

hCG (Human Chorionic Gonadotropin)

Gonadotropin (LH-receptor agonist glycoprotein hormone)

hCG is a placental glycoprotein hormone that acts on the same receptor as luteinizing hormone, and it is used in fertility and male hypogonadism medicine.

5000 IU vial · Commonly reported three times weekly (for example Mon/Wed/Fri)