Mechanism
Kisspeptin & GnRH axis
Kisspeptins, products of the KISS1 gene, act on the KISS1R receptor on hypothalamic neurons to release gonadotropin-releasing hormone (GnRH). GnRH then acts on pituitary gonadotrophs to release LH and FSH, which drive the ovaries and testes. The axis responds to pulses: pulsatile signals stimulate it, while continuous exposure can desensitise or suppress it. Kisspeptin peptides act one step upstream of GnRH.
How the members differ
- Kisspeptin-10 is the shortest kisspeptin sequence with full activity at KISS1R; its human data are physiological studies in healthy men.
- Kisspeptin-54 is the 54-amino-acid form, used in phase 2 IVF trials and sexual-desire studies, and has been tested as a nasal spray.
- Gonadorelin is identical to native GnRH; it was a US human product, now discontinued, and is still marketed as a veterinary drug.
- Long-acting GnRH analogues such as leuprolide suppress the axis under continuous exposure, so they are not interchangeable with gonadorelin.
Compounds in this group
LeuprolideHuman trial evidence · FDA-approvedLeuprolide (leuprorelin) is a synthetic GnRH agonist nonapeptide, FDA-approved in depot and injectable forms (Lupron Depot, Eligard, Camcevi, Fensolvi and generics) for advanced prostate cancer, endometriosis, fibroid-related anemia and central precocious puberty.
TriptorelinHuman trial evidence · FDA-approvedTriptorelin is a synthetic decapeptide GnRH agonist, FDA-approved (initial U.S. approval 2000) as Trelstar for advanced prostate cancer and as Triptodur for central precocious puberty in children 2 years and older.
Kisspeptin-10Limited human data · Not approved — research use onlyA short peptide fragment of kisspeptin, the KISS1 gene product, studied in research on reproductive neuroendocrine signaling.
Kisspeptin-54Limited human data · Not approved — research use onlyKisspeptin-54 (metastin) is the 54-amino-acid form of the hypothalamic peptide kisspeptin, which acts on the KISS1R (GPR54) receptor to drive GnRH and downstream LH and FSH release. Academic human studies have given it intravenously, subcutaneously and intranasally to healthy volunteers, women with hypothalamic amenorrhoea and women undergoing IVF, where it was used to trigger oocyte maturation. It is not approved for any use and is prohibited in sport; this entry summarizes the published studies for research reference only.
GonadorelinLimited human data · Approved, no longer marketedGonadorelin is a synthetic form of gonadotropin-releasing hormone (GnRH), studied in research on the hypothalamic-pituitary-gonadal axis.
Compare Leuprolide, Triptorelin, Kisspeptin-10 side by side
For research use only. Not for human or veterinary use. Not a drug, food, or dietary supplement. Mechanism descriptions summarize published research and are not claims of effect in people.