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Hormonal & reproductive

Gonadorelin

Also called GnRH, LHRH, gonadotropin-releasing hormone, Factrel

Gonadorelin is a synthetic copy of GnRH, the brain hormone that tells the pituitary to release LH and FSH. It was FDA-approved in 1982 as Factrel, mainly as a diagnostic test of pituitary function, but that product is now discontinued in the US. Some men's-health clinics use compounded versions alongside testosterone therapy.

FDA-approvedApproved by the FDA for at least one use after large human trials.

All printable flashcards

Drawn from its published sequence: 10 residues, one bead each.

Overview

Gonadorelin is a synthetic copy of GnRH, the brain hormone that tells the pituitary to release LH and FSH. It was FDA-approved in 1982 as Factrel, mainly as a diagnostic test of pituitary function, but that product is now discontinued in the US. Some men's-health clinics use compounded versions alongside testosterone therapy.

How it works

Established: it binds GnRH receptors on the pituitary, causing release of LH and FSH. Pulsed dosing stimulates the reproductive axis, while continuous exposure can eventually suppress it.

What research shows

  • Approved uses: diagnostic testing of hypothalamic-pituitary function and inducing ovulation in women lacking natural GnRH release 2.
  • Use in men on testosterone therapy is off-label and not supported by an FDA-approved indication.

Doses studied in people

Study or labelDose usedSource
US labeling (as summarized in Drugs.com/Micromedex monograph), diagnostic test of hypothalamic-pituitary function, adults0.1 mg as a single subcutaneous or intravenous injection2
US labeling (as summarized in Drugs.com/Micromedex monograph), Lutrepulse pump for amenorrhea/infertility of hypothalamic origin, adults5 mcg intravenously by pump every 90 minutes for 21 days (adjustable by the physician)2

Doses are from US labeling as summarized in a Drugs.com/Micromedex monograph (original Factrel/Lutrepulse labels not retrieved); both products are discontinued in the US, and no approved dose exists for use alongside testosterone therapy.

Read this first: these are the amounts given to participants in published studies or written on official prescribing labels, reported for reference. They are not recommendations. Trial doses were chosen for specific patients under medical supervision, and a dose that is safe in one person can be harmful in another.

Safety

  • With repeated doses, report breathing trouble, persistent flushing or rapid heartbeat right away 2.
  • Injection-site reactions, rash, brief flushing, headache, lightheadedness and nausea are reported 2.

Report side effects of any drug or product to the FDA through MedWatch. For a possible poisoning in the US, call Poison Control at 1-800-222-1222.

History

FDA approved Factrel (gonadorelin hydrochloride, NDA 018123) on September 30, 1982 in 0.1, 0.2 and 0.5 mg vials; all strengths are now on FDA's discontinued list. It has been used to test hypothalamic-pituitary function and to induce ovulation in women with hypothalamic amenorrhea.

Common questions

Is gonadorelin FDA-approved?

It was approved in 1982 as Factrel, but that product is now discontinued in the US 12.

What was gonadorelin approved for?

It was used to test how well the brain's hormone control center and the pituitary gland are working, and to start ovulation in women whose bodies do not release enough natural GnRH 2.

What doses appear on the US label?

As summarized from US labeling, the diagnostic test used a single 0.1 mg injection under the skin or into a vein, and the Lutrepulse pump gave 5 mcg into a vein every 90 minutes for 21 days 2. Both products are discontinued, and no approved dose exists for use alongside testosterone therapy 2.

What side effects are reported?

Reported effects include injection-site reactions, rash, brief flushing, headache, lightheadedness and nausea 2. With repeated doses, breathing trouble, ongoing flushing or a racing heartbeat should be reported right away 2.

Is gonadorelin banned in sport?

Yes. WADA prohibits it at all times under S2.2.1, which names gonadotrophin-releasing hormone (GnRH, gonadorelin) among peptides that raise testosterone in males 4.

Can gonadorelin be compounded?

It is not on FDA's 503A nominations list as of May 2026, so whether pharmacies may compound it depends on other 503A rules, and current status should be checked 3.

Related compounds

Hormonal & reproductiveEarly human dataFlashcard

Kisspeptin-10

KP-10 · metastin 45-54

Kisspeptin-10 is the shortest active piece of kisspeptin, a natural hormone that acts as the 'on switch' for the brain's reproductive hormone system.

Sources

  1. FDA Orange Book listing: Factrel (NDA 018123) Regulatory
  2. Drugs.com (Micromedex): Gonadorelin (intravenous, injection) — includes labeled dosing Reference
  3. FDA: Bulk Drug Substances Nominated for Use in Compounding Under Section 503A (updated May 14, 2026) Regulatory
  4. WADA 2026 Prohibited List (official English text, Dutch Treaty Series Trb. 2026, 25) Regulatory

Last reviewed 2026-10-25 · How we research · Found an error? See our corrections policy.