KPV: What the Published Research Actually Shows
A three-residue fragment of alpha-MSH with a genuinely unresolved mechanism — here's what's been verified about its identity, and what the preclinical literature does and doesn't support.
This article discusses published preclinical and in vitro research on KPV. It is educational only and does not constitute medical, regulatory or legal advice. KPV is supplied by Velyx strictly for laboratory research purposes and is not licensed as a medicine for human use in the UK.
KPV is one of the smaller peptides discussed in research contexts, and also one of the more mechanistically unsettled — the published literature genuinely hasn't converged on how it produces the cellular effects it's been observed to produce. This article sets out what's verifiable about its identity, what the preclinical studies actually measured, and where the mechanism remains an open question rather than settled science.
What Is KPV?
KPV is the common shorthand for the tripeptide L-lysyl-L-prolyl-L-valine (Lys-Pro-Val) — the C-terminal three residues (positions 11–13) of alpha-melanocyte-stimulating hormone (α-MSH). It's also catalogued as "MSH (11-13)."
- Molecular formula: C₁₆H₂₉N₃O₄ is sometimes seen online but is incorrect for the free tripeptide; the correct formula, matching PubChem CID 125672, is C₁₆H₃₀N₄O₄.
- Molecular weight: ≈342.4 g/mol
- CAS number: 67727-97-3
- PubChem CID: 125672 ("Msh (11-13)")
We've cross-checked these identifiers against PubChem directly rather than repeating figures circulating on other research-supplier pages — a different CID (13294447) also circulates online and does not correspond to this compound.
How It's Thought to Work — and What's Actually Unresolved
KPV is often described as acting through melanocortin receptors, the same receptor family α-MSH itself signals through. That's an oversimplification worth being precise about. The classical melanocortin receptor pharmacophore is the His-Phe-Arg-Trp (positions 6–9) sequence within α-MSH — and KPV, as residues 11–13, doesn't contain it. Whether and how KPV engages melanocortin receptors is a genuinely open research question, not a settled mechanism.
Two separate lines of published evidence bear on this directly:
- Receptor signalling data is inconclusive. Elliott et al. (2004, Journal of Investigative Dermatology) tested KPV and related MSH fragments in human keratinocyte and CHO cell systems and reported no detectable cyclic-AMP elevation from KPV — the classical readout for melanocortin receptor activation — in contrast to full-length ACTH and α-MSH, which did produce that response in the same assay system.
- A transporter-mediated route has been proposed instead. Dalmasso et al. (2008, Gastroenterology) found that KPV is taken up by intestinal epithelial cells and lymphocytes via PepT1, a peptide transporter, rather than acting at the cell surface — with downstream effects on NF-κB and MAPK signalling measured once the peptide was inside the cell.
Put plainly: the cellular effects attributed to KPV in preclinical models are reasonably well documented, but the receptor-level explanation for how they occur is not settled in the literature the way it is for many other peptides.
What the Published Preclinical Research Shows
All of the research below is preclinical — cell culture and rodent models. We have not found a registered human clinical trial for KPV on ClinicalTrials.gov, and none is implied below.
| Study | Model | What Was Measured |
|---|---|---|
| Dalmasso et al., 2008, Gastroenterology | Mouse colitis models (DSS/TNBS); intestinal epithelial cells & lymphocytes | PepT1-mediated uptake; cytokine expression; myeloperoxidase activity |
| Kannengiesser et al., 2008, Inflammatory Bowel Diseases | Murine models of inflammatory bowel disease | Body weight, colon histology, myeloperoxidase activity |
| Human bronchial epithelial cell study (PMCID: PMC3403564) | Human bronchial epithelial cells | Inflammatory signalling cues; role of MC3R agonists alongside KPV |
| Elliott et al., 2004, Journal of Investigative Dermatology | Human keratinocytes; CHO cells | Cyclic AMP, intracellular calcium signalling |
A related but distinct compound, the cyclic dimer (CKPV)₂, has also been studied (Gatti et al., 2006) in LPS-challenged rat models and human PBMCs, with TNF-α and nitrite concentration as endpoints. It's worth being precise that (CKPV)₂ is a different, cysteine-linked molecule from the linear KPV tripeptide — findings on one don't automatically transfer to the other, even though both derive from the same MSH C-terminal sequence.
Formulation & Analytical Research
A validated stability-indicating HPLC method for tracking KPV in aqueous solution and skin homogenates has been published (Pawar et al., 2015, Biomedical Chromatography). This is an analytical chemistry method designed to detect and monitor the compound during laboratory analysis; it should not be interpreted as establishing a specific degradation rate under all storage or experimental conditions.
Separately, Sun et al. (2021) developed a cross-linked hydrogel delivery system for KPV, tested in a TNBS-induced colitis model in rats. This work investigated a particular experimental formulation and delivery system and should not be interpreted as establishing an appropriate formulation, route or use for other research settings.
These studies illustrate an important distinction between analytical or formulation research and evidence of biological effectiveness. Experimental findings from a particular laboratory system should not automatically be generalised to other models or to human use.
Where the Evidence Is Weaker
The entire evidence base for KPV sits in cell culture and rodent models. There is no published human clinical trial data we could locate, and the receptor mechanism itself — whether melanocortin receptor-mediated, transporter-mediated, or some combination — remains unresolved in the primary literature.
Claims that treat KPV's mechanism as settled, or that extrapolate rodent colitis-model findings to any human outcome, go beyond what the cited studies show.
UK Regulatory Considerations
KPV is not an MHRA-authorised medicine for human use in the UK. The regulatory position of a research compound can depend on the substance itself, how it is presented or marketed, its stated or intended purpose, and the legislation that applies in the relevant circumstances.
This article does not make a legal determination regarding the lawful supply, possession or use of KPV. Researchers with a specific regulatory question should consult current UK legislation and official regulatory guidance and obtain appropriate professional advice where necessary.
For a broader discussion of the regulatory considerations surrounding research peptides, see our article on research peptides and UK regulation .
In Summary
KPV has a small but genuine preclinical research trail — rodent colitis models, keratinocyte and bronchial epithelial cell signalling studies, and analytical research examining the compound in laboratory systems.
What it doesn't have is a settled receptor mechanism or published human clinical trial data. Any framing that skips past that mechanistic uncertainty is presenting the research as more resolved than it is.
References
[1] Dalmasso, G., Charrier-Hisamuddin, L., Nguyen, H.T.T., et al. (2008). PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation. Gastroenterology, 134(1), 166–178. PMID: 18061177.
[2] Kannengiesser, K., Maaser, C., Heidemann, J., et al. (2008). Melanocortin-derived tripeptide KPV has anti-inflammatory potential in murine models of inflammatory bowel disease. Inflammatory Bowel Diseases, 14(3), 324–331. PMID: 18092346.
[3] Inhibition of cellular and systemic inflammation cues in human bronchial epithelial cells by melanocortin-related peptides: mechanism of KPV action and a role for MC3R agonists. PMCID: PMC3403564.
[4] Elliott, R.J., Szabo, M., Wagner, M.J., et al. (2004). α-Melanocyte-stimulating hormone, MSH 11-13 KPV and adrenocorticotropic hormone signalling in human keratinocyte cells. Journal of Investigative Dermatology. PMID: 15102092.
[5] Gatti, S., Colombo, G., Buffa, P., et al. (2006). Inhibitory effects of the peptide (CKPV)₂ on endotoxin-induced host reactions. Journal of Surgical Research. PMID: 16413580.
[6] Pawar, H., Mulabagal, V., & Fujii, S. (2015). Stability-indicating HPLC assay for lysine-proline-valine (KPV) in aqueous solutions and skin homogenates. Biomedical Chromatography. PMID: 25298219.
[7] Sun, Y., et al. (2021). Self-cross-linked hydrogel of cysteamine-grafted γ-polyglutamic acid stabilized tripeptide KPV for alleviating TNBS-induced ulcerative colitis in rats. PMID: 34547895.
Frequently Asked Questions
Is KPV the same as alpha-MSH?
No. KPV is a three-amino-acid fragment corresponding to just the C-terminal end (residues 11–13) of the 13-amino-acid alpha-MSH peptide. It lacks the His-Phe-Arg-Trp sequence that alpha-MSH uses to bind melanocortin receptors.
Does KPV bind melanocortin receptors?
This isn't settled in the literature. KPV lacks the core melanocortin receptor-binding motif, and at least one published study found no detectable cyclic-AMP response (the standard melanocortin receptor signalling readout) from KPV in keratinocytes. A separate line of research instead points to transporter-mediated cellular uptake via PepT1. Both mechanisms have been studied; neither is conclusively established as the primary pathway.
Is (CKPV)₂ the same compound as KPV?
No. (CKPV)₂ is a cyclic, cysteine-linked dimer — a structurally distinct molecule from the linear KPV tripeptide, studied separately in the literature. Findings reported for one should not be assumed to apply to the other.
Has KPV been tested in human clinical trials?
We were unable to locate a registered human clinical trial for KPV on ClinicalTrials.gov. The published evidence base is limited to cell culture and rodent studies.
What is KPV's regulatory status in the UK?
KPV is not an MHRA-authorised medicine for human use in the UK. The regulatory position of a research compound depends on the substance, how it is presented or marketed, its intended purpose and the legislation that applies. This article does not provide a legal determination regarding the supply or use of KPV.