MensResearch OnlyNot For Human Consumption

Gonadorelin

GnRH · Luteinising Hormone-Releasing Hormone · LHRH

The brain's own signal for testosterone production, used in research to keep the testes working during or after testosterone therapy.

MECHANISM OF ACTION

Gonadorelin is a synthetic copy of a natural brain signal (GnRH, gonadotropin-releasing hormone) that your hypothalamus normally sends in regular pulses to the pituitary gland. Those pulses tell the pituitary to release LH and FSH, hormones that travel to the testes and tell them to produce testosterone and sperm. The critical point: it only works when given in pulses. If given continuously without breaks, the pituitary gets overwhelmed and actually shuts down, the opposite of what you want. When men use testosterone therapy, their brain naturally stops sending GnRH signals (because it detects enough testosterone already), which can cause the testes to shrink and sperm production to stop. Pulsatile gonadorelin keeps the testes receiving their activation signal, preserving their function.

RESEARCH APPLICATIONS

  • Testicular function preservation during androgen therapy
  • HPG axis restoration research
  • Spermatogenesis support models
  • Hypogonadotropic hypogonadism research
  • Pulsatile GnRH receptor pharmacology

RESEARCH HIGHLIGHTS

Testicular Volume Preservation

2006

Pulsatile gonadorelin during TRT prevented the testicular atrophy seen with exogenous testosterone alone, maintaining Sertoli cell function and spermatogenesis in most subjects.

Ref: Liu et al., JCEM

RESEARCH PROTOCOL NOTES

Research doses100–500 mcg pulsatile SC (every 60–90 min via pump, or simplified daily dosing in research)
Critical noteContinuous/depot = suppression. Pulsatile = stimulation. Dosing frequency determines outcome.
Available formatsVial (2mg - BodyPharm Gonadorelin)

Chemical Identity

Molecular FormulaC55H75N17O13
Molecular Weight1182.3 g/mol
CAS Number33515-09-2
SolubilitySoluble in water

Sequence

pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2

Storage & Stability

Lyophilised: -20°C. Reconstituted: 2–8°C, 7–14 days. Very short plasma half-life makes careful reconstitution timing important.

Regulatory Status

Approved as Factrel (Pfizer) for diagnostic use. Compounded versions used in fertility and men's health contexts. SA: Schedule 4/research compound depending on indication. WADA: prohibited under S2.