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Gonadorelin

low risk

Also: GnRH · Luteinizing hormone-releasing hormone (LHRH) · Factrel

Strong Evidence FDA Approved

Gonadorelin is synthetic GnRH — the hypothalamic hormone that stimulates LH and FSH release. FDA-approved. Widely used off-label as a TRT adjunct to maintain testicular function and fertility in testosterone users. The pulsatile dosing requirement is critical to efficacy.

Molecular Weight
1182.3 Da
Formula
C55H75N17O13
Common Dosing
100 mcg SC/IM twice weekly (TRT adjunct, off-label); pulsatile delivery preferred
Category
therapeutic
Last Reviewed
2025-01-15

Reported Benefits

LH/FSH stimulation

Strong Evidence 45 studies

Well-characterized pituitary stimulation; used diagnostically and therapeutically.

Fertility preservation during TRT

Moderate Evidence 22 studies

Maintains intratesticular testosterone and spermatogenesis in exogenous testosterone users.

Testicular atrophy prevention

Moderate Evidence 18 studies

Preserves testicular volume and function in men on TRT vs. TRT alone.

Mechanism of Action

Binds GnRH receptors on pituitary gonadotrophs; stimulates LH and FSH release, driving testicular testosterone production and spermatogenesis. Continuous dosing causes receptor downregulation (desensitization).

Key Clinical Studies

Hsieh et al. (2013)

Retrospective cohort · n=26

PubMed →

Maintained azoospermia reversal and testicular volume in TRT users on gonadorelin

The TRT Adjunct Use Case

Exogenous testosterone suppresses the HPG axis, shutting down natural LH/FSH production and causing testicular atrophy and infertility. Twice-weekly pulsatile gonadorelin maintains LH/FSH signaling, preserving testicular function during TRT — a critical quality-of-life and fertility consideration.

Pulsatile vs. Continuous: Critical Distinction

Continuous GnRH stimulation downregulates pituitary receptors and paradoxically causes hypogonadism (the basis of prostate cancer treatment with GnRH agonists). Pulsatile delivery (twice weekly or similar) maintains receptor sensitivity and net stimulation.

Regulatory Status

FDA Approved

FDA approved (Factrel). 503A listed for compounding.

Safety Profile

Side Effects

  • •Injection site reactions
  • •Hot flashes
  • •Headache
  • •Desensitization with continuous dosing

Contraindications

  • •Hormone-sensitive cancers
  • •Pregnancy

Drug Interactions

  • •Testosterone therapies
  • •Sex steroid supplements

Primary Uses

HypogonadismTestosterone support (TRT adjunct)FertilityTesticular atrophy prevention

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Disclaimer: This information is for educational and research purposes only. Not medical advice. Consult a qualified healthcare provider before using any compound.