What is kisspeptin?

Kisspeptin is an endogenous peptide hormone encoded by the KISS1 gene. Cells make a 145-residue precursor and cleave it into kisspeptin-54, -14, -13 and -10. The shared C-terminal decapeptide carries the activity, and kisspeptin-10, the smallest isoform, is reported to activate the receptor fully. ^[1]

The molecule began as a cancer gene. In 1996 a Pennsylvania State University group in Hershey isolated a gene they called KiSS-1 from melanoma cells whose ability to metastasise had been suppressed. ^[8] The Society for Endocrinology's patient site says the name honours the chocolate Kisses made in Hershey. ^[9] In 2001 Takeda scientists isolated the 54-residue peptide from human placenta and named it metastin. ^[10] The same year a Brussels group isolated the 54, 14 and 13-residue forms and named them kisspeptins. ^[11] Kisspeptin-10 still carries the synonym metastin 45-54 from that period. ^[3]

Research vials sold as kisspeptin, ours included, are listed as kisspeptin-10. The certificate's mass result confirms which form a vial holds. Kisspeptin in 10mg vials is in stock with a batch certificate.

Kisspeptin binds KISS1R, a G protein-coupled receptor, and drives the hypothalamus to release gonadotrophin-releasing hormone (GnRH). GnRH then stimulates the pituitary to release luteinising hormone (LH) and follicle-stimulating hormone (FSH). ^[9] Imperial College researchers describe kisspeptin-10 and kisspeptin-54 as hormones that stimulate endogenous GnRH secretion from the hypothalamus. ^[12]

The receptor pharmacology comes from 2001. The Brussels group reported that the kisspeptins bound rat and human GPR54 with low nanomolar affinities and triggered calcium mobilisation and MAP kinase signalling in cultured cells. ^[11] A 2015 review adds that the different kisspeptins bind the receptor with equal efficacy. ^[13]

Where it acts matters for how researchers read their results:

• Two hypothalamic populations. Kisspeptin neurons sit in the arcuate and anteroventral periventricular nuclei. Oestrogen feeds back negatively through the first and positively through the second. ^[13]
• KNDy neurons. Arcuate neurons release kisspeptin with neurokinin B and dynorphin, and are nicknamed KNDy ("candy"). ^[9]
• Genetic proof. In 2003 two groups found that loss-of-function mutations in GPR54 cause hypogonadotropic hypogonadism. ^[14][15] Gpr54-deficient mice showed the same picture and still responded to GnRH. ^[15] A 2008 review calls the receptor an "indisputable gatekeeper" of reproductive function. ^[16]

The genetics are the strongest part of the kisspeptin story. They show the receptor is required for normal puberty in people. They say nothing about what an added peptide does over time.

Kisspeptin-10 is a linear decapeptide, Tyr-Asn-Trp-Asn-Ser-Phe-Gly-Leu-Arg-Phe, with an amidated C-terminus. PubChem's systematic synonym spells it out as L-tyrosyl-L-asparaginyl-L-tryptophyl-L-asparaginyl-L-seryl-L-phenylalanyl-glycyl-L-leucyl-L-arginyl-L-phenylalaninamide. ^[3]

The kisspeptin-10 column comes from PubChem ^[3] and the kisspeptin-54 column from its separate PubChem record. ^[17] We checked each value on 29 September 2026. Counted from the full 145-residue precursor, kisspeptin-10 is residues 112 to 121. ^[18]

Two details are worth knowing before you handle a vial. First, the two forms differ by more than 4,500 g/mol, so a mass spectrometry result separates them at a glance. Second, the sequence holds a tryptophan at position 3 and asparagines at positions 2 and 4, residues that matter for storage (covered below).

Kisspeptin has been examined in cell and animal work, human genetics and small human physiology studies. In the studies reviewed here, the human pharmacology came from groups in Edinburgh and London, and the larger trials used kisspeptin-54. The longest kisspeptin-10 exposure in people ran 22.5 hours. ^[2]

The 2011 Edinburgh study is the core kisspeptin-10 paper. Its authors note that kisspeptin-10 had not been studied in men before. During a continuous infusion in four men, testosterone rose from 16.6 to 24.0 nmol/L and LH pulse frequency rose from 0.7 to 1.0 pulses per hour. ^[2] The 2011 Imperial study found no change in LH or FSH in women studied in the follicular phase. ^[4]

Every finding above describes what one study reported in its own participants. None of it is a claim about a research vial.

The evidence shows that kisspeptin releases LH and FSH within minutes in controlled settings. It leaves four large gaps.

1. The kisspeptin-10 studies are tiny. Groups held four to six people, and the 2015 comparison lists its small sample size as its main limitation. ^[12]
2. Repeated exposure blunts the response. In women with hypothalamic amenorrhoea, the LH response fell by about 90% over two weeks, while the pituitary still responded to GnRH. ^[20] No kisspeptin-10 study tested repeated exposure in people.
3. The response depends on sex and hormonal phase. Women in the follicular phase showed no response to kisspeptin-10 in the 2011 study. ^[4]
4. Clinical use remains research. A 2025 review of IVF triggers says kisspeptin's use "remains predominantly within the research setting", limited to early-phase or highly selected studies. ^[23]

The cancer history is also narrower than it sounds. The metastasis-suppressor findings come from melanoma cell lines and a mouse metastasis model. ^[8][10] They describe the gene's discovery. No human cancer trial sits behind them in this record.

The human kisspeptin-10 abstracts reviewed here (PMIDs 21632807, 21976724 and 26089302) report no adverse-event data at all. They were short hormone-response studies in healthy volunteers, and silence in an abstract is an absence of reporting.

The other published records cover different models or a different isoform:

• Dogs, kisspeptin-10 (2021). A 14-day toxicology study with a 14-day recovery period reported no overt signs of drug-related toxicity in clinical signs, body weight, food consumption, clinical pathology, histopathology, urinalysis, ECG or respiratory rate. The highest level tested was classed as the no-observed-adverse-effect level. ^[21]
• Humans, kisspeptin-54 (2025). In the intranasal crossover trial, the authors reported that no adverse events were encountered in healthy men, healthy women or women with hypothalamic amenorrhoea. ^[22] Kisspeptin-54 is a different molecule, so this record does not transfer to kisspeptin-10.
• Humans, kisspeptin-54 IVF trial (2015). Among 60 women at high risk of ovarian hyperstimulation syndrome, no woman developed moderate, severe or critical ovarian hyperstimulation. ^[5]
• Desensitisation (2009). Repeated kisspeptin-54 exposure reduced the LH response by day 14, a pharmacological effect the authors flagged as important for further development. ^[20]

These are the records the published abstracts contain. They are small, short and mostly from one group, and they describe trial conditions only.

Kisspeptin is not named in the Poisons Standard. We searched the June 2026 instrument (F2026L00633), which commenced on 1 June 2026, for "kisspeptin" and "metastin" and found no entry. Schedule 4 runs from khellin and kitasamycin to labetalol with nothing between. ^[6] Its neighbours in the reproductive axis are scheduled: gonadorelin and human chorionic gonadotrophin both sit in Schedule 4. ^[6]

"Not named" is a narrow finding. Schedule 4 also carries a general entry for gonadotrophic hormones, ^[6] and the TGA states that a "research use only" label does not change whether a product is regulated as a therapeutic good. ^[24] Our guide to Australian peptide law and the Poisons Standard explains what each schedule means.

For sport, the answer is plain. The WADA 2026 Prohibited List, effective 1 January 2026, places "kisspeptin and its agonist analogues" in S2.2.1, testosterone-stimulating peptides in males. S2 substances are prohibited at all times, in and out of competition. ^[7] Anti-doping laboratories test for it: a 2026 Ghent method for 54 prohibited compounds in blood includes kisspeptin-10. ^[25] Some overseas explainers still say kisspeptin is absent from the List; the 2026 text names it.

The three compounds act at three levels of the same axis. Kisspeptin works at the hypothalamus, gonadorelin (GnRH) at the pituitary, and hCG stands in for the LH surge at the ovary. ^[12][26]

The masses come from PubChem ^[3][27] and the legal rows from the Poisons Standard and the WADA List. ^[6][7]

Two direct comparisons exist. In healthy men, GnRH produced about 3-fold more LH than kisspeptin-10 and about 2-fold more than kisspeptin-54. ^[12] In IVF research, a 2021 meta-analysis pooled randomised trials that compared kisspeptin, and other triggers, against conventional hCG. ^[26] A 2025 review notes that hCG remains the most widely used trigger and carries a significant risk of ovarian hyperstimulation. ^[23] Research-grade hCG and kisspeptin both sit in our hormone research peptides range.

Keep lyophilised kisspeptin-10 sealed, dry, dark and frozen. No published stability study covers lyophilised research-grade kisspeptin-10, so the general peptide guidance applies: -20°C for short-term storage and -80°C for longer, away from bright light, with the vial brought to room temperature before opening. ^[28]

The sequence adds two specific risks. Sigma-Aldrich lists tryptophan (W) among the residues prone to air oxidation, and asparagine (N) and tryptophan among residues unstable in solution. ^[28] Kisspeptin-10 has one tryptophan and two asparagines. Solutions therefore deserve more care than the powder.

Biological samples show how quickly the peptide breaks down once dissolved:

• In rat plasma, kisspeptin-10 decomposed with half-lives of 6.8, 2.9 and 1.7 minutes at 4, 25 and 37°C. The main product had lost its N-terminal tyrosine. ^[18]
• In human serum and plasma, kisspeptin-10 was extensively degraded after one week at 4 and 22°C, while blood samples held stable for at least two months at -20°C. ^[25]

For solvents, the same guide recommends sterile distilled water or sterile dilute acetic acid (0.1%) for a stock solution, split into aliquots so you avoid repeated freezing and thawing. ^[28] We stock BAC Water and acetic acid in 3ml vials at A$8 each. Our peptide storage guide covers temperatures and labelling, and the reconstitution guide covers solvent choice and concentration arithmetic.

Peptides Collective sells kisspeptin for laboratory research use only, in 10mg vials from A$85. Stock ships from Western Australia with tracking.

Every batch is tested by an independent lab before it goes on sale. The certificate reports purity by HPLC and identity by mass spectrometry, and it is published under the batch number printed on the vial. Search the certificate of analysis library by that number to match the report to the vial in your hand.

Read the identity result against the structure table. A kisspeptin-10 vial should show a mass near 1302 g/mol; a value near 5857 g/mol would mean the 54-residue form. Our guide on how to read a peptide certificate of analysis explains the HPLC trace, the mass spectrum and net peptide content. The kisspeptin product page links the certificate for the current batch.

Kisspeptin is the KISS1-derived peptide family that sits at the top of the reproductive hormone axis, and kisspeptin-10 is its 10-residue active core. Human work shows fast LH and FSH release in small, short studies, with a blunted response on repeated exposure and no response in some women. It is not named in the Australian Poisons Standard and WADA prohibits it at all times in males. For a research vial, the batch certificate settles what is inside.