What is gonadorelin?
Gonadorelin is the nonproprietary name for synthetic gonadotropin-releasing hormone (GnRH), also called luteinizing hormone-releasing hormone (LHRH). The gonadorelin peptide has ten residues, and most papers call it GnRH or LHRH. In 1971 a group isolated a polypeptide from porcine hypothalami that released both luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitaries of several species.
They identified it as (pyro)Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH₂, synthesized it, and found that natural and synthetic material shared biological properties (Schally et al., 1971). Disguised Alpha does not currently list gonadorelin; this page is a literature reference for laboratory researchers. Nothing on this page is guidance for use in people.
Gonadorelin reference data
| Property | Value |
|---|---|
| Name | Gonadorelin |
| Also called | Gonadotropin-releasing hormone (GnRH), GnRH-I, luteinizing hormone-releasing hormone (LHRH, LH-RH), LH-releasing factor (LRF), gonadoliberin I, mammalian GnRH (PubChem CID 638793 and the cited papers) |
| Sequence | pGlu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH₂: ten residues, with an N-terminal pyroglutamate and a C-terminal glycinamide |
| Compound class | Hypothalamic decapeptide hormone; synthetic GnRH and an agonist at the GnRH receptor |
| Molecular formula | C₅₅H₇₅N₁₇O₁₃ (peptide); gonadorelin acetate C₅₇H₇₉N₁₇O₁₅; gonadorelin hydrochloride C₅₅H₇₆ClN₁₇O₁₃ |
| Molecular weight | 1182.3 g/mol (peptide); 1242.3 g/mol (acetate); 1218.7 g/mol (hydrochloride) |
All identity data come from PubChem: CID 638793 for the peptide, CID 11980076 for gonadorelin acetate and CID 23624131 for gonadorelin hydrochloride. PubChem records the acetate with one acetic acid per peptide and also holds diacetate (CID 56841073) and diacetate tetrahydrate (CID 72941601) records, so the peptide content per milligram of powder depends on the salt form.
See it beside the other compounds on this site in the peptide molecular weight reference table.
What the research covers
Published work on gonadorelin falls into six areas. Each summary below states the model used. Mechanistic work is mostly animal and cell data; human studies appear as research history.
Discovery and sequence
Two laboratories reported the structure in 1971 and 1972. The porcine work concluded that one hypothalamic peptide regulates the secretion of both LH and FSH (Schally et al., 1971). A second group sequenced the ovine hormone by enzymatic digestion, Edman-dansyl sequencing and mass spectrometry. A synthetic copy matched the native factor's activity, and the ovine sequence proved identical to the porcine one (Burgus et al., 1972). Models: porcine and ovine hypothalamic extracts, with pituitary assays in several species.
The GnRH receptor and pituitary desensitization
A mouse GnRH receptor cDNA, expressed in Xenopus oocytes, produced a functional, high-affinity receptor. The 327-residue protein has the seven transmembrane domains of G protein-coupled receptors but lacks a typical intracellular C-terminal tail, which the authors suggested may explain unusual aspects of its signaling and regulation (Tsutsumi et al., 1992).
In superfused rat anterior pituitary cells, continuous 30 nM GnRH first raised LH and FSH secretion 20-fold, then secretion fell to basal levels within 12 hours, while pulses kept the cells responsive for more than 24 hours (Smith and Vale, 1981). Models: Xenopus oocytes and rat pituitary cells.
Pulsatile versus continuous delivery
In rhesus monkeys whose hypothalamic lesions abolished gonadotropin release, a constant GnRH infusion failed to restore sustained gonadotropin secretion, while one pulse per hour restored it. The pattern of delivery, not the amount, decided the effect, and switching restored animals to continuous infusion could produce desensitization (Belchetz et al., 1978).
In a follow-up study, raising the pulse frequency to two, three or five per hour lowered LH and FSH by shrinking the response to each pulse, while slowing pulses to one every 3 hours raised FSH as LH fell variably (Wildt et al., 1981). Model: rhesus monkeys.
Clearance and longer-acting analogs
Native GnRH is cleared within minutes. In a 1977 infusion study, its first-phase half-disappearance time was 5.5 to 8 minutes in healthy volunteers and 12 to 16.5 minutes in chronic renal failure, and the authors suggested that the kidney may be an important site of breakdown or that uremia may slow breakdown non-specifically (Pimstone et al., 1977).
Rat membrane enzymes degraded native GnRH much faster than the analog D-Phe6-GnRH, whose biological half-life in rats was 2.5 times longer, and no intact GnRH appeared in rat urine (Berger et al., 1991). Models: a human infusion study; rat tissues and rats.
Veterinary reproduction research in cattle
Gonadorelin and other GnRH analogs are widely used in cattle to synchronize estrus and induce ovulation (Picard-Hagen et al., 2015). In a 1995 protocol pairing GnRH with prostaglandin F2α, the first GnRH step caused ovulation in 18 of 20 lactating cows and 13 of 24 heifers (Pursley et al., 1995).
Across the four gonadorelin products then sold in the United States, the share of lactating cows ovulating ranged from 55.3% to 85.0%, with no detectable differences in LH profiles (Souza et al., 2009). In 12 Holstein cows, gonadorelin's mean LH peak was 2.5 times lower than with lecirelin or buserelin, yet the share of cows whose dominant follicle disappeared did not differ significantly between the compounds (Picard-Hagen et al., 2015). Model: dairy cattle.
Human research history
By 1972 the synthetic decapeptide was being tested in volunteers. In 23 healthy adults, serum LH peaked 20 to 30 minutes after a rapid intravenous bolus, FSH rose much less, and growth hormone, thyrotrophin and ACTH did not change; the authors proposed the response as a test of pituitary function (Besser et al., 1972).
Drugs@FDA lists two US human drug applications for gonadorelin salts, a hydrochloride (original approval 1982) and an acetate (1989), and marks both products as discontinued (FDA, NDA 018123; FDA, NDA 019687). A 2015 case report describes severe anaphylaxis within 3 minutes of intravenous gonadorelin acetate during an LH-RH stimulation test in an 8-year-old (Akın et al., 2015). Models: healthy adult volunteers; a pediatric case report.
Key studies
- Schally AV, et al. "Gonadotropin-releasing hormone: one polypeptide regulates secretion of luteinizing and follicle-stimulating hormones." Science. 1971. PMID 4938639. DOI 10.1126/science.173.4001.1036. Porcine hypothalamic peptide, sequenced and synthesized: one hormone releases LH and FSH.
- Belchetz PE, et al. "Hypophysial responses to continuous and intermittent delivery of hypothalamic gonadotropin-releasing hormone." Science. 1978. PMID 100883. DOI 10.1126/science.100883. Lesioned rhesus monkeys: hourly pulses restored gonadotropin secretion; continuous infusion did not.
- Wildt L, et al. "Frequency and amplitude of gonadotropin-releasing hormone stimulation and gonadotropin secretion in the rhesus monkey." Endocrinology. 1981. PMID 6788538. DOI 10.1210/endo-109-2-376. Rhesus monkeys: pulse frequency and amplitude set LH and FSH levels and their ratio.
- Smith MA, Vale WW. "Desensitization to gonadotropin-releasing hormone observed in superfused pituitary cells on Cytodex beads." Endocrinology. 1981. PMID 7007026. DOI 10.1210/endo-108-3-752. Rat pituitary cells: continuous exposure desensitized them; pulses did not.
- Souza AH, et al. "Comparison of gonadorelin products in lactating dairy cows: efficacy based on induction of ovulation of an accessory follicle and circulating luteinizing hormone profiles." Theriogenology. 2009. PMID 19394072. DOI 10.1016/j.theriogenology.2009.02.016. Lactating dairy cows: ovulation response differed among four products.
- Hoitink MA, et al. "Degradation kinetics of gonadorelin in aqueous solution." J Pharm Sci. 1996. PMID 8897270. DOI 10.1021/js9601187. HPLC and LC-MS kinetics: most stable at pH 5 to 5.5.
Handling and storage of lyophilized gonadorelin
General laboratory practice for a lyophilized peptide of this kind, in line with the site's peptide storage guide and peptide reconstitution guide:
- Keep sealed powder dry, at -20°C and protected from light. Let a cold vial reach room temperature before opening so moisture does not condense on the cake.
- Dissolve it in the diluent your protocol names, run the liquid down the vial wall, and swirl rather than shake.
- Mind the pH. In water, gonadorelin is most stable near pH 5 (Helm and Müller, 1990); at pH 5 to 5.5 and 70°C its half-life was 70 days (Hoitink et al., 1996). The two studies differed on buffers: the first found faster degradation in phosphate than in acetate, while the second found that buffer concentration, phosphate included, did not change the rate.
- Hold solutions at 2 to 8°C in single-use aliquots and avoid freeze-thaw cycles.
- Record the salt form and lot, since salt forms carry different amounts of peptide per milligram.
Frequently asked questions
What is gonadorelin?
Gonadorelin is synthetic gonadotropin-releasing hormone, the hypothalamic decapeptide that regulates the release of LH and FSH from the pituitary (Schally et al., 1971). In the mammalian literature, GnRH, LHRH and gonadorelin name the same sequence.
Is gonadorelin a peptide?
Yes. The gonadorelin peptide has ten amino acid residues, with a pyroglutamate at the N-terminus and a glycinamide at the C-terminus. PubChem's ChEBI entry (CID 638793) classes it as an oligopeptide and a peptide hormone with a role as a GnRH agonist.
What is gonadorelin acetate?
It is the same decapeptide as an acetate salt. PubChem CID 11980076 lists it as C₅₇H₇₉N₁₇O₁₅, 1242.3 g/mol, against 1182.3 g/mol for the free peptide. The acetate and the hydrochloride are the salts in the two US human drug applications described above.
How does gonadorelin differ from longer-acting GnRH agonists?
Gonadorelin keeps the native sequence and is cleared within minutes (Pimstone et al., 1977). Superactive agonists carry a D-amino acid at position 6, and their higher activity is attributed to greater receptor affinity and resistance to breakdown (Berger et al., 1991). In cattle, gonadorelin released less LH than buserelin or lecirelin (Picard-Hagen et al., 2015).
Is gonadorelin on the WADA Prohibited List?
Yes. The 2026 World Anti-Doping Agency Prohibited List names gonadorelin in section S2.2.1, under peptide hormones and their releasing factors. That section applies to male athletes, and class S2 is prohibited at all times, in and out of competition (WADA Prohibited List, 2026).
Does Disguised Alpha sell gonadorelin?
Not currently. The catalog does include kisspeptin, which acts one step upstream: in sheep, kisspeptin delivered into the brain ventricles released GnRH into cerebrospinal fluid with a parallel rise in serum LH, and in mice lacking its receptor, GPR54, it did not raise LH or FSH (Messager et al., 2005). See the kisspeptin research guide.
Related compounds and guides
- Kisspeptin research guide: the peptide that drives GnRH release through GPR54
- Peptide storage guide
- Peptide reconstitution guide
- What is a peptide?
- Peptide molecular weight reference table
This page summarizes published research for laboratory reference only. Disguised Alpha does not currently sell gonadorelin, and nothing here is medical or veterinary advice or guidance for use in people or animals.