Short answer
What is Kisspeptin-10? Kisspeptin-10 is a synthetic decapeptide corresponding to the C-terminal ten residues of kisspeptin-54 (metastin), ending in an RF-amide motif. It is the endogenous agonist of the G-protein-coupled receptor KISS1R (GPR54) and is studied in laboratory research as the minimal active fragment of the kisspeptin family. It is sold as a lyophilized research powder and is not for human use.
What is Kisspeptin-10?
Kisspeptin-10 is a ten-residue peptide with the sequence Tyr-Asn-Trp-Asn-Ser-Phe-Gly-Leu-Arg-Phe-NH2 (YNWNSFGLRF-NH2). It is the C-terminal fragment of the larger kisspeptin peptides produced from the product of the KISS1 gene, a locus first identified as a metastasis-suppressor gene in melanoma research [1][2].
The kisspeptin family includes kisspeptin-54 (also called metastin), kisspeptin-14, kisspeptin-13, and kisspeptin-10. All of them share the same C-terminal sequence and end in an arginine-phenylalanine-amide (RF-amide) motif that is essential for receptor activation. Kisspeptin-10 is the minimal fragment that retains full agonist activity at the kisspeptin receptor, which makes it the most economical synthetic tool for routine receptor studies [2][3].
Chemical characterization: the RF-amide decapeptide
Kisspeptin-10 is a linear decapeptide with a C-terminal amide and a molecular mass of approximately 1302 Da. The amidated C-terminus is required for activity: the RF-amide motif is the critical address that the receptor recognizes, and non-amidated versions of kisspeptin peptides lose activity at KISS1R [2].
Because it is a short, linear peptide, kisspeptin-10 is straightforward to synthesize by solid-phase methods and is widely available as a lyophilized salt (typically a trifluoroacetate form) for reconstitution in laboratory buffers. Its small size means that identity can be confirmed quickly by mass spectrometry, and purity by HPLC is typically high for commercial research lots.
This structural simplicity is one reason kisspeptin-10 is preferred over the full-length kisspeptin-54 in many assays. The shorter peptide is cheaper to produce, easier to characterize, and retains essentially the same receptor pharmacology, so most in vitro work on the kisspeptin system is carried out with kisspeptin-10 [2][3].
KISS1R (GPR54): the kisspeptin receptor
KISS1R, previously known as GPR54 and early on as hOT7T175, is a G-protein-coupled receptor that was still an orphan receptor when the kisspeptins were identified as its endogenous ligands in 2001 [1][2]. Two independent reports that year established that the product of the KISS1 gene encodes the cognate ligands:
Kisspeptin-10, being the common C-terminal ten residues, reproduces this pharmacology: it binds KISS1R with low-nanomolar affinity, activates Gq/phospholipase C signaling, and raises intracellular calcium. This makes kisspeptin-10 a convenient, cost-effective agonist for KISS1R assays [2][3].
Kisspeptin research: the decapeptide reproductive axis
The most important discovery in kisspeptin research came when it was recognized that KISS1R is a master regulator of the reproductive neuroendocrine axis. Kisspeptins are synthesized in specific hypothalamic neuron populations and act on gonadotropin-releasing hormone (GnRH) neurons, which express KISS1R. Activation of KISS1R on GnRH neurons triggers the pulsatile release of GnRH, which in turn drives the secretion of the gonadotropins from the pituitary and governs the activity of the gonads [3][4].
This places kisspeptin signaling at the top of a hierarchical circuit that controls puberty timing and the adult function of the reproductive axis. Inactivating mutations in KISS1R cause a profound form of hypogonadotropic hypogonadism, and the same phenotype is seen in Kiss1r-deficient mice, confirming that the receptor is essential for normal reproductive neuroendocrine function [3][4].
The wiring of this circuit has been mapped in considerable detail. Kisspeptin neurons in the hypothalamus send projections that directly contact GnRH neuron cell bodies and dendrites, and the kisspeptin receptors on GnRH neurons are the point at which the system converts neuronal activity into pulsatile neuropeptide output. This anatomical and functional coupling is why the kisspeptin/KISS1R system is described as a gatekeeper of the reproductive axis, and it is also why kisspeptin-10, as a receptor-level agonist, is such a widely used reagent: it allows the experimenter to bypass the endogenous ligand supply and directly challenge the receptor in a controlled manner [3][4].
For laboratory researchers, kisspeptin-10 is therefore used primarily as a tool to probe GnRH neuron activity in vitro. It provides a well-defined agonist for studying the calcium and electrical responses of GnRH neurons, the coupling of KISS1R to intracellular signaling, and the molecular pharmacology of the receptor in heterologous expression systems.
Research history
The history of kisspeptin research spans two phases. The first phase was the discovery of the KISS1 gene and its ligand, driven by metastasis-suppressor biology in melanoma cell lines; the two 2001 papers that identified metastin and the kisspeptins closed the gap between the gene and its receptor [1][2]. The second phase was the recognition of the neuroendocrine phenotype, led by the discovery that KISS1R mutations cause isolated hypogonadotropic hypogonadism, followed by the demonstration that kisspeptin application to animal models potently stimulates GnRH neuron firing and gonadotropin release [3][4].
A comprehensive review by Pinilla and colleagues in Physiological Reviews summarizes the molecular biology, signaling pathways, and neuroendocrine roles of the kisspeptin/KISS1R system across vertebrates [3]. Pineda and colleagues provide a focused overview of the neuroendocrine control of reproduction, situating kisspeptin signaling at the apex of the axis [4].
What research shows about kisspeptin-10 as a tool
The published literature supports several reproducible findings that researchers rely on when using kisspeptin-10:
For laboratories working on neuroendocrinology, kisspeptin-10 is most valuable as a reproducible positive control for KISS1R agonism and as a physiological ligand for studies of GnRH neuron function. When combined with receptor antagonists or receptor-negative cell lines, kisspeptin-10 can also be used to confirm that an observed response is genuinely KISS1R-dependent rather than mediated by another pathway.
Kisspeptin-10 compared with related research peptides
For a broader overview of neuropeptide tool molecules, see the neuropeptide research category, and for a general introduction to peptides, our what are peptides guide.
How to evaluate research-grade Kisspeptin-10
When sourcing kisspeptin-10 for laboratory work, verify the same quality markers as for any research peptide:
For a detailed look at what a peptide COA should contain, see our peptide COA guide, and for a comparison of the analytical methods used to verify purity, our article on HPLC versus mass spectrometry for peptide purity.
Storage and handling
Lyophilized kisspeptin-10 is stable when stored correctly. Standard laboratory handling guidance applies:
For a step-by-step protocol, see our peptide reconstitution and laboratory handling guide, and for general storage recommendations, our how to store peptides guide.
Summary
Kisspeptin-10 is a well-characterized RF-amide decapeptide and the minimal active fragment of the kisspeptin family. It is the endogenous agonist of KISS1R (GPR54), a Gq-coupled receptor whose activation on GnRH neurons makes it a master regulator of the reproductive neuroendocrine axis. Its simple linear structure, low-nanomolar affinity, and defined signaling pathway make it the standard laboratory tool for KISS1R assays. Research-grade material should be verified for HPLC purity, mass-spectrometry identity, and batch-specific COA, and handled according to standard lyophilized-peptide protocols.
FAQ
What is Kisspeptin-10?
Kisspeptin-10 is a synthetic decapeptide corresponding to the C-terminal ten residues of kisspeptin-54 (metastin), ending in an RF-amide motif, and is the endogenous agonist of KISS1R (GPR54).
Why is the RF-amide motif important?
The C-terminal arginine-phenylalanine-amide motif is essential for receptor recognition and activation; non-amidated versions of kisspeptin peptides lose activity at KISS1R.
What receptor does Kisspeptin-10 activate?
Kisspeptin-10 activates KISS1R, previously known as GPR54 (and early on as hOT7T175), a Gq-coupled G-protein-coupled receptor expressed on GnRH neurons.
What purity should research-grade Kisspeptin-10 have?
At least 98-99% by HPLC, with identity confirmed by mass spectrometry and a batch-specific COA.