Kisspeptin-10 is a 10-amino-acid peptide (sequence YNWNSFGLRF) and the shortest active fragment of kisspeptin, the protein encoded by the KISS1 gene. Its older name, metastin 45-54, comes from its discovery in cancer-metastasis research before its reproductive role was understood. You'll also see it sold as KP-10. PubChem lists it under CID 25240297, molecular formula C63H83N17O14.
Despite being a small fragment, KP-10 keeps the part of the molecule that does the work. It binds the receptor KISS1R (also called GPR54), which sits on gonadotropin-releasing hormone (GnRH) neurons in the hypothalamus. Activating that receptor drives GnRH release, which signals the pituitary to put out luteinizing hormone (LH) and follicle-stimulating hormone (FSH). In short, kisspeptin acts one step upstream of GnRH and is a gatekeeper of the hypothalamic-pituitary-gonadal axis. People born with loss-of-function mutations in KISS1 or its receptor fail to go through puberty, which is how the pathway's importance was pinned down. A review in Frontiers in Endocrinology (2022) covers this control system in detail.
What the human research shows
Kisspeptin is unusual among research peptides in that it has a real clinical track record, largely from the group at Imperial College London. First-in-human kisspeptin studies were done in men in 2005 and women in 2007.
A direct head-to-head trial gives the clearest picture of KP-10 specifically. Jayasena and colleagues, publishing in Human Reproduction (2015), infused kisspeptin-10, kisspeptin-54, and GnRH into healthy men at matched doses. Two findings stand out:
- GnRH was more potent. At the top dose, LH rose roughly 3-fold higher with GnRH than with KP-10.
- KP-10 clears fast. Its plasma half-life was about 4 minutes, versus roughly 28 minutes for the longer kisspeptin-54. The two kisspeptins produced broadly similar effects despite that gap.
That short half-life is the practical catch with KP-10. It's a clean tool for probing the axis, but a fleeting signal is awkward for treatment. Much of the translational work has therefore used kisspeptin-54 or longer-acting analogs such as MVT-602.
The conditions under study are reproductive. Kisspeptin can trigger the LH surge that matures eggs during IVF, and because it works through the body's own physiology rather than a sustained synthetic signal, researchers have looked at whether it lowers the risk of ovarian hyperstimulation syndrome compared with standard hCG triggers. A 2022 review by Sharma, Dhillo, Abbara and colleagues in Frontiers in Endocrinology lays out that case. Kisspeptin is also being studied in functional hypothalamic amenorrhea, where chronic dosing runs into tachyphylaxis (the response fades with repeated exposure).
Regulatory and quality notes
Kisspeptin-10 is not an approved drug. It is sold as a research chemical and is labeled for research use only, not for human consumption. None of the above is medical or dosing advice.
For anyone evaluating material sold under this name, identity and purity are the things a certificate of analysis should actually document. KP-10 is a specific decapeptide, and it is easy to confuse with kisspeptin-54 or rat-sequence variants, which differ chemically. A credible COA shows mass spectrometry confirming the correct molecular weight and HPLC purity for the human sequence. peptideone aggregates independent third-party rater data where it exists; treat unverified vendor claims with caution.