What is Gonadorelin?

What sources report

What it is

Gonadorelin is a synthetic decapeptide, made by solid-phase peptide synthesis, with the same sequence as natural GnRH.¹ That sequence is pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2: it starts with pyroglutamic acid and ends in glycinamide.⁵¹⁶ In the body, the GNRH1 gene makes a precursor protein that is cut to release gonadoliberin-1, and mutations in this gene are associated with hypogonadotropic hypogonadism.² The peptide has been supplied as two salts: Factrel used the hydrochloride, while Lutrepulse Kit and the cattle product GONAbreed use the acetate.³¹⁷ PubChem lists gonadorelin at 1182.3 g/mol and its acetate record at 1242.3 g/mol.¹⁸¹⁹

How it acts

Gonadorelin works on the pituitary gland.¹ DrugBank states that it mainly stimulates the making and release of LH, and the gene record adds FSH.¹⁰² An FDA-approved cattle label describes the same action: the injection releases the animal's own LH.²⁰ In males, LH drives the Leydig cells of the testes to make androgens, as the label of hCG explains for a drug whose action it calls virtually identical to pituitary LH.¹¹

The delivery pattern decides the result: in rhesus monkeys with hypothalamic lesions, one pulse of synthetic GnRH per hour restored pituitary hormone release, while a constant infusion failed to sustain it.²¹ The authors traced the difference to the pattern of delivery, not the amount.²¹ Continuous exposure desensitizes the pituitary's gonadotropin-making cells.¹ Gonadorelin also clears fast, with an initial half-life of 2 to 10 minutes, so clinical treatment relied on infusion pumps.¹⁰

What human studies show

Human use has been supervised and narrow: single IV doses to test pituitary function, and pump pulses to replace a missing GnRH signal.¹¹⁰¹³

• Ovulation (systematic review of 35 studies, 1,002 women, 2018): in hypothalamic amenorrhea, pulsatile GnRH appeared to achieve high ovulation rates, and pulses under the skin worked about as well as IV pulses.¹²
• Pregnancy (clinical practice guideline, 2017): in case series cited by the Endocrine Society, 75% of pulsatile GnRH cycles were ovulatory in one, and another reported pregnancy in 29% of cycles in women with no other infertility factors.²²
• PCOS (randomized trial, 30 women, 2013): in hypothalamic amenorrhea plus PCOS, ovarian response was similar with pulsatile GnRH and with FSH plus LH (73% vs 60%), but clinical pregnancy was 46% against 0%.²⁴ A Cochrane review of 4 trials with 57 women was too small to prove or rule out a benefit in PCOS.²⁵
• Male fertility (nonrandomized study, 28 men, 2019): in congenital hypogonadotropic hypogonadism, sperm appeared sooner with a gonadorelin pump than with cyclical gonadotropins (median 6 against 14 months). Over 24 months, 90% of 10 men and 83.3% of 18 men produced sperm, not a significant difference.⁹ A 2024 review puts sperm induction at 75% to 80% of such men with either approach, though semen usually stays below normal WHO values.²⁶
• Bone (observational study, 22 men, 2015): spine and hip bone mineral density rose after 6 months of pulsatile gonadorelin.²⁷ Before treatment, 45.45% of the patients had osteoporosis, against 10.00% of 20 healthy controls.²⁷
• Pituitary testing (records review, 234 girls, 2018): girls checked for central precocious puberty had LH and FSH measured for 90 minutes after one IV dose, with a peak LH above 5.0 U/L as the diagnostic cutoff.¹³

What has not been studied

The sources behind this page include no study of gonadorelin in healthy people, in men taking testosterone, or with injections given 1 to 3 times a week. Whether such injections maintain LH, testosterone, testicular size or sperm output in any group is unknown. Pulse therapy itself was not available in the US when the Endocrine Society published its 2017 guideline.²²

How it compares

• Kisspeptin acts one step earlier: it stimulates GnRH-induced gonadotropin release and regulates the pubertal activation of GnRH nerve cells.²⁸ More on What is Kisspeptin-10?
• hCG acts one step later, like LH on the testes, and has current FDA-approved products such as Novarel.¹¹ More on What is HCG?
• Leuprolide (Lupron Depot) is a long-acting GnRH analog: sex steroids rise at first, then monthly dosing lowers gonadal steroid output.¹⁵
• Gonadotropin injections for ovulation: in one nonrandomized comparison cited by the Endocrine Society, multiple pregnancies followed 8.3% of GnRH cycles and 14.8% of gonadotropin cycles, a difference that was not statistically significant.²²

The goal pages on testosterone, men's health and women's health set gonadorelin beside other compounds. Researchers who need the peptide itself can find Gonadorelin for sale as a 2 mg vial of gonadorelin acetate.

Side effects

Gonadorelin's safety record comes from supervised clinical use, mostly in studies of 1 to 36 people plus one meta-analysis of 1,002 women.^1223929 None of the sources reviewed reports safety data for self-injected research-grade gonadorelin.

Reported with clinical use, by frequency

• Common: skin reactions at the pump needle. Authors of the 2019 study call skin allergic erythema scleroma (redness with hardened skin) a common side effect of the pump, and report red induration around the needle in some men.⁹⁸
• Occasional: fever with IV pumps. Among 36 women on IV pulses over 113 cycles, 6 had 8 febrile episodes that settled quickly with antibiotics and a cannula change, with no serious complications.²³
• Rare: superficial thrombophlebitis, an inflamed surface vein, with IV pulses.¹²
• Extremely rare but serious: anaphylaxis. An 8-year-old girl lost consciousness and had tonic seizures within 3 minutes of IV gonadorelin acetate, then recovered after epinephrine, diphenhydramine and fluids.²⁹

Risks tied to fertility treatment

• Multiple pregnancy: low with pulsatile GnRH but slightly above the general population.¹² One IV series had 4 twin pregnancies among 24 births.²³
• Ovarian hyperstimulation syndrome (OHSS): low in incidence and mild with pulsatile GnRH.¹² In the PCOS trials it was seen only in women given HMG, a gonadotropin.²⁵

Warnings

• Constant exposure blunts the response: continuous gonadorelin desensitizes the pituitary, and in monkeys a constant infusion failed to sustain hormone release.¹²¹
• Allergy: the case authors advise that anaphylaxis should be anticipated with IV gonadorelin acetate, and that it be given where systemic reactions can be treated.²⁹
• Not for people: the GONAbreed label states it is not for use in humans, and the Zoetis Factrel label says not for human use.¹⁷²⁰
• Unknowns: safety in pregnancy and breastfeeding, antibody formation with long-term use and drug interactions are not covered by the sources reviewed.

General precautions for research peptides are in peptide safety basics.

Dosage information

No human dose of gonadorelin is established for any current use. The discontinued human products have no label on file at Drugs@FDA, and DailyMed lists no human gonadorelin label, so labeled human doses could not be sourced.³⁰³¹⁷ The remaining FDA-approved gonadorelin products are cattle drugs.⁴ The figures below come from supervised studies and an animal label. They show what was given, not what anyone should use.

How research doses are reported in general is covered in peptide dosage basics.

Reconstitution and storage

No human mixing directions are on file, because Drugs@FDA holds no label for Factrel or Lutrepulse Kit.³⁰³¹ The published handling facts come from cattle labels and one lab study:

• GONAbreed (gonadorelin acetate solution): each mL holds 100 mcg of gonadorelin and 10 mg of benzyl alcohol.¹⁷ Unopened vials stay refrigerated. Once opened, it may be kept at up to 25 °C (77 °F), and what remains is discarded 180 days after first use.¹⁷
• Factrel for cattle (Zoetis, gonadorelin hydrochloride solution): kept at 2 to 8 °C (36 to 46 °F), with excursions to 25 °C (77 °F) permitted, and used within 1 month of the first vial puncture.²⁰
• Solution chemistry (lab study, 1990): breakdown was slowest at about pH 5.0; acetate buffers helped and phosphate buffers hurt.³³ In a 0.1 M acetate buffer at pH 5.0 with 3% mannitol, the predicted time before 10% was lost was 9.0 years at 20 °C.³³ That figure applies to that buffered formula only.

These are facts about labeled solutions and lab chemistry, not instructions for use in people. The lab steps for mixing a vial are in the reconstitution guide, the reconstitution calculator handles the concentration math, and how to store peptides covers general storage practice.

Regulatory status

The Endocrine Society's 2017 guideline on functional hypothalamic amenorrhea suggests pulsatile GnRH as a first-line way to induce ovulation, a weak recommendation based on very low-quality evidence, but states that GnRH therapy is not currently available in the United States.²² The approved cattle uses, set out in 21 CFR 522.1077, are ovarian follicular cysts in dairy cattle and, with cloprostenol sodium, timing estrous cycles for fixed-time artificial insemination.⁴

For compounding, gonadorelin acetate sits under evaluation on FDA's 503B list.³⁴ Gonadorelin is absent from FDA's list of substances that may present significant safety risks, a list that does name kisspeptin-10, GHRP-2, GHRP-6 and ipamorelin acetate.³⁶ In a June 17, 2026 warning letter, FDA named a 'Gonadorelin' sold online by Wholesale Peptide as an unapproved new drug, although its labels read 'RESEARCH USE ONLY' and 'not for human consumption'.³⁹ In an August 24, 2026 letter to another online seller, FDA found the products were drugs for human use despite 'for research use only' and 'not for human or veterinary use' labels.³⁸

In sport, the WADA 2026 Prohibited List names GnRH (gonadorelin) and its agonist analogues under S2.2.1, testosterone-stimulating peptides in males, prohibited in and out of competition.⁶ Outside the US, a 2018 study gave IV Relefact, a gonadorelin acetate product from Sanofi-Aventis in Frankfurt, Germany, and WHO assigns gonadorelin the ATC codes H01CA01 and V04CM01.¹³¹⁰ Approval status country by country was not checked for this page.