KPV Research

KPV research splits into two unequal halves. The preclinical literature is substantial, covering inflammation, gut biology and wound models. No published study has administered KPV to a person. That absence is not an inference from a failed search. FDA searched PubMed, Embase, ClinicalTrials.gov and its own adverse-event and complaint systems through December 2025 and recorded the absence formally.^[1] This article describes what has been published, not outcomes anyone should expect.

What KPV is

KPV is the tripeptide lysine-proline-valine, corresponding to residues 11 to 13 of alpha-melanocyte-stimulating hormone (alpha-MSH). CAS 67727-97-3 designates the free acid, H-Lys-Pro-Val-OH, recorded by PubChem as CID 125672, C16H30N4O4, 342.43 g/mol. FDA's July 2026 briefing document lists the same three values.^[1] Research-grade KPV is usually supplied as the acetate salt.

Alpha-MSH is amidated at its C-terminus, so its literal C-terminal fragment is KPV-NH2 (PubChem CID 7019758). The free acid under this CAS is a des-amido analog of that fragment. The CAS does not reliably separate the two in trade. FDA's characterization footnotes cite a supplier offering the amide, Lys-Pro-Val-NH2, under CAS 67727-97-3.^[1]

Several near neighbors circulate under similar names:

• Ac-Lys-Pro-Val-NH2, the acetylated amide used in much of the founding 1980s work.^[2]
• (Ac-CKPV)2, a disulfide-linked dimer described in 2006 as under clinical investigation.^[3]
• KdPT (Lys-D-Pro-Thr), a KPV derivative corresponding to residues 193 to 195 of IL-1beta.
• GKPV, the tetrapeptide alpha-MSH(10-13).

None of these is KPV, and FDA excluded studies of N-acetylated KPV and of the dimer from its evaluation as out of scope.^[1]

How KPV is thought to work

A central finding in KPV mechanism research is a negative one. KPV does not appear to bind melanocortin receptors. Lyson and colleagues found that alpha-MSH(11-13) did not inhibit binding of a radiolabeled alpha-MSH analog to melanoma cells.^[4] Tatro and Entwistle found no competition at brain melanocortin receptors.^[5] Both binding studies were in vitro. Mandrika and colleagues found no competition at MC1R sites across the range tested, up to millimolar, and no cAMP response.^[6] Alpha-MSH raised cAMP in those same in vitro experiments.

Getting and colleagues tested the point in animals. KPV reduced leukocyte accumulation in mouse peritonitis models, but the effect survived an MC3/MC4 antagonist and persisted in mice with non-functional MC1R.^[7] An MC1R-selective agonist was inactive in that model, and KPV failed to raise cAMP or to inhibit KC and IL-1beta release from macrophages in vitro. The authors concluded KPV is unlikely to act through melanocortin receptors.

Alpha-MSH receptor pharmacology therefore cannot be read across to KPV. The two share three residues, but KPV does not reproduce the melanocortin receptor behavior of its parent. A 2010 review states that KPV lacks the entire sequence motif required for binding to any known melanocortin receptor.^[8]

An intracellular mechanism has been proposed instead. In human bronchial epithelial cells in vitro, KPV suppressed NF-kappaB signaling and cytokine release.^[9] The authors attributed this to nuclear import of the peptide and interference with the importin-alpha3 binding site on p65RelA. That intracellular model is proposed rather than established.

The receptor-free account has published opposition. Kelly and colleagues immobilized the related tetrapeptide GKPV on beads, which prevented cell entry.^[10] It still inhibited TNF-alpha-stimulated NF-kappaB activity in vitro in one of two culture conditions.^[10] They concluded the peptide acts through a cell-surface receptor mechanism. Elliott and colleagues found no cAMP response to KPV in human keratinocytes in vitro, but reported that MC1R-transfected CHO cells did show a calcium rise to KPV.^[11] In the keratinocytes themselves, calcium responses appeared only alongside a drug that blocks the cAMP pathway.^[11] KPV's mechanism of action remains unsettled.

Preclinical KPV research

The best-developed line concerns the gut. Dalmasso and colleagues showed that nanomolar KPV suppressed NF-kappaB and MAP kinase signaling in human intestinal epithelial cell lines in vitro. Uptake in those cells occurred through the di- and tripeptide transporter PepT1, and oral KPV reduced dextran sulfate sodium and TNBS colitis in mice.^[12] Kannengiesser and colleagues reproduced the benefit in dextran sulfate sodium colitis and in a transfer-colitis model.^[13] The first of those is the same model Dalmasso used, so only the transfer model is a further one. A second group has therefore reproduced the colitis benefit in animals.

Viennois and colleagues reported that KPV suppressed colitis-associated tumorigenesis in mice, and the same paper carries its own null.^[14] The effect was entirely absent in PepT1-knockout mice. An effect gated on a transporter concentrated in gut epithelium is a poor fit for claims of systemic action.

Animal work exists outside the gut. Topical KPV accelerated corneal epithelial wound healing after mechanical abrasion in rabbits.^[15] That report states eight of eight corneas treated with KPV or the nitric oxide donor sodium nitroprusside re-epithelialized fully. None of the placebo corneas re-epithelialized, and the report gives no denominator for that arm. Blocking nitric oxide synthase inhibited the KPV effect, and totally prevented the sodium nitroprusside effect.^[15] A single injection of alpha-MSH(11-13) after experimental traumatic brain injury reduced lesion volume and neuronal apoptosis in mice, although TNF-alpha and IL-1beta expression were not reduced.^[16] A 2026 mouse study reported reduced body-weight gain and adipose expansion on a high-fat diet, with supporting preadipocyte work in vitro.^[17] In vitro work published since 2025 includes a keratinocyte and 3D skin model series.^[18]

An early null came from the founding laboratory. In mice, alpha-MSH and a D-valine-substituted analog of alpha-MSH(11-13) inhibited inflammation induced by IL-1beta, IL-6 and TNF-alpha.^[19] The abstract names only the full peptide for the failure, reporting that alpha-MSH(1-13) did not alter inflammation caused by LTB4, PAF or IL-8.^[19] The tripeptide tested in that study was the D-valine-substituted analog rather than KPV.

A separate line of animal work raises a specificity question. Uehara and colleagues reported that alpha-MSH(11-13) blocked interleukin-1-induced anorexia in animals, and only at the higher of the two amounts tested.^[20] The same group later reported that the dipeptide lysine-proline attenuated IL-1beta-induced anorexia in rats.^[21] If a two-residue fragment reproduces the effect, the activity may not belong to the KPV sequence specifically.

The antimicrobial claim is disputed

Cutuli and colleagues reported that alpha-MSH peptides including KPV killed Staphylococcus aureus and Candida albicans at picomolar concentrations in vitro.^[22] That paper drew a published comment contesting the anti-Candida finding, with an author reply.^[23] Songok and colleagues later reported no antimicrobial activity under a variety of in vitro conditions, but they tested Ac-KPV-NH2 rather than KPV.^[24]

A third result cuts against a simple null. Singh and Mukhopadhyay found alpha-MSH(11-13) killed over 90 percent of methicillin-sensitive and methicillin-resistant S. aureus in the micromolar range in vitro.^[25] Activity was comparable to whole alpha-MSH, while the N-terminal fragment alpha-MSH(1-5) was ineffective.^[25] Charnley and colleagues, however, found potency did not depend on the lysine residue and assigned the activity to a generic X-Pro-D/L-Val motif in vitro.^[26] Their test articles were alpha-MSH and acetylated amide tripeptides, including Ac-Lys-Pro-Val-NH2, rather than free-acid KPV.^[26] The antimicrobial question is unresolved.

Human research on KPV

No published study has administered KPV to a human being. No trial of KPV appears in ClinicalTrials.gov or ISRCTN. PubMed indexes no clinical trial, randomized controlled trial, systematic review or meta-analysis of KPV. FDA stated it had not identified any human exposure data on drug products containing KPV by any route.^[1] FDA also identified no pharmacokinetic, toxicokinetic, acute or repeat-dose toxicity, genotoxicity, reproductive or carcinogenicity study of KPV.^[1]

One study is sometimes presented as human data. Catania and colleagues added alpha-MSH(11-13) to whole blood drawn from HIV-infected patients and measured LPS-stimulated cytokine production, which fell concentration-dependently.^[27] Nothing was administered to any person, so that is an ex vivo experiment on human tissue.

A second confusion involves a different molecule. KdPT was tested in a randomized double-blind Phase IIa add-on trial in mild-to-moderate ulcerative colitis.^[28] The abstract states the primary endpoint was met after additional analyses, against a very high placebo rate after week 4. That is a qualified result on a sibling peptide, not KPV evidence.

Delivery is a further constraint. Passive permeation of KPV through human cadaver skin was below the limit of detection ex vivo, and microporation or iontophoresis was required to move measurable amounts across.^[29] FDA noted this could limit KPV's usefulness as a topical agent.^[1]

Regulatory status and limitations

Neither KPV free base nor KPV acetate is a component of an FDA-approved drug.^[1] KPV was nominated for FDA's section 503A bulks list by a commercial compounding pharmacy and placed in FDA's Category 2. That category holds bulk drug substances that may present significant safety risks. The nominator then withdrew the nomination. FDA reopened the evaluation on its own initiative, and its briefing document for the July 2026 Pharmacy Compounding Advisory Committee proposed not adding KPV free base or KPV acetate.^[1] The committee vote had not been published as of late August 2026. Claims of a favorable committee outcome circulating on retailer sites are not supported by anything FDA has published.

FDA's stated concern for the Category 2 peptides is aggregation and immunogenicity, with no human data available to rule either out.^[1] FDA identified no immunogenicity study and no aggregation study of KPV.^[1] It notes that peptides as short as two amino acids have been shown to aggregate.^[1] FDA also concluded that neither substance is well characterized from a physical and chemical perspective.^[1] It found no impurity profile, no aggregate testing and no microbiological testing in any certificate of analysis available to it.^[1]

Bulk-ingredient drug listings are sometimes cited as evidence of approval, and they are not. Seven openFDA listings name KPV or KPV acetate under bulk-ingredient categories, and six of the seven declare an unrelated 14-residue peptide as their active ingredient. FDA's adverse-event and complaint systems returned zero reports for KPV, which is not a safety finding.^[1] FDA notes in the same document that compounders generally do not report adverse events to it.^[1]

One further FDA record cuts against a common retail claim. Outsourcing facilities reported compounding no drug product containing KPV free base or KPV acetate from January 2017 through June 2025, alone or in combination.^[1] Those figures come from FDA's outsourcing facility product report database, which does not capture every compounder.^[1] They still weigh against retailer claims that KPV is widely compounded.

Conflicts of interest run through the secondary literature. Much of the favorable review writing comes from one melanocortin group with a long-standing program in these tripeptides. Those reviews argue a position rather than report new results.^[8][30] The founding anti-inflammatory work came from a laboratory whose commercial development effort went to the (Ac-CKPV)2 dimer rather than to KPV.^[3] Because no USP or NF monograph and no adequate certificate of analysis exist, FDA's own physicochemical figures for KPV were drawn largely from peptide vendor pages.^[1]

Conclusion

KPV has a substantial preclinical record and no published record of administration to a human being. Three independent groups found no melanocortin receptor binding by KPV in vitro. Two later reports point instead toward a cell-surface site. Its mechanism remains unsettled. Among the animal results described here, only the colitis benefit has been reproduced by a second group. Its best-evidenced effects depend on uptake through an intestinal transporter. Beyond that preclinical work, FDA identified no human exposure data and no toxicology studies, and it found no applicable USP or NF monograph.^[1]

Frequently Asked Questions

Has KPV been studied in humans? No published study has administered KPV to a human being, by any route, and FDA stated it had not identified any human exposure data on drug products containing KPV.^[1] One ex vivo study added alpha-MSH(11-13) to blood drawn from patients, but nothing was administered to any person.^[27]

Is KPV the same as the C-terminal tripeptide of alpha-MSH? Not exactly, and the difference is one amide group. Alpha-MSH is amidated at its C-terminus, so its literal C-terminal fragment is KPV-NH2. CAS 67727-97-3 designates the free acid, a des-amido analog of that fragment. That CAS does not reliably separate the two in trade, and FDA's characterization footnotes cite a supplier offering the amide under it.^[1]

Has the colitis finding been independently replicated? Yes, in animals. Dalmasso and colleagues reported that oral KPV reduced dextran sulfate sodium and TNBS colitis in mice.^[12] Kannengiesser and colleagues reproduced the benefit in dextran sulfate sodium colitis and in a transfer-colitis model.^[13] Both are animal findings, and no human colitis study of KPV exists.

Is KPV an FDA-approved drug? No. Neither KPV free base nor KPV acetate is a component of an FDA-approved drug.^[1] FDA's July 2026 briefing document proposed not adding either to the section 503A bulks list.^[1] The advisory committee vote had not been published as of late August 2026.

References

1. 1

   FDA. Briefing Document: KPV-Related Bulk Drug Substances, Pharmacy Compounding Advisory Committee, 23-24 July 2026. https://www.fda.gov/media/193346/download (regulatory document, no PMID or DOI)
2. 2

   Deeter LB, et al. Antipyretic properties of centrally administered alpha-MSH fragments in the rabbit. Peptides. 1988. PMID 2854626.
3. 3

   Gatti S, et al. Inhibitory effects of the peptide (CKPV)2 on endotoxin-induced host reactions. J Surg Res. 2006. PMID 16413580.
4. 4

   Lyson K, et al. Binding of anti-inflammatory alpha-melanocyte-stimulating-hormone peptides and proinflammatory cytokines to receptors on melanoma cells. Neuroimmunomodulation. 1994. PMID 7489322.
5. 5

   Tatro JB, Entwistle ML. Heterogeneity of brain melanocortin receptors suggested by differential ligand binding in situ. Brain Res. 1994. PMID 8173950.
6. 6

   Mandrika I, et al. Effects of melanocortin peptides on lipopolysaccharide/interferon-gamma-induced NF-kappaB DNA binding and nitric oxide production in macrophage-like RAW 264.7 cells. Biochem Pharmacol. 2001. PMID 11239505.
7. 7

   Getting SJ, et al. Dissection of the anti-inflammatory effect of the core and C-terminal (KPV) alpha-melanocyte-stimulating hormone peptides. J Pharmacol Exp Ther. 2003. PMID 12750433.
8. 8

   Brzoska T, et al. Terminal signal: anti-inflammatory effects of alpha-melanocyte-stimulating hormone related peptides beyond the pharmacophore. Adv Exp Med Biol. 2010. PMID 21222263.
9. 9

   Land SC. Inhibition of cellular and systemic inflammation cues in human bronchial epithelial cells by melanocortin-related peptides. Int J Physiol Pathophysiol Pharmacol. 2012. PMID 22837805.
10. 10

    Kelly JM, et al. Immobilized alpha-melanocyte stimulating hormone 10-13 (GKPV) inhibits tumor necrosis factor-alpha stimulated NF-kappaB activity. Peptides. 2006. PMID 16274845.
11. 11

    Elliott RJ, et al. Alpha-melanocyte-stimulating hormone, MSH 11-13 KPV and adrenocorticotropic hormone signalling in human keratinocyte cells. J Invest Dermatol. 2004. PMID 15102092.
12. 12

    Dalmasso G, et al. PepT1-mediated tripeptide KPV uptake reduces intestinal inflammation. Gastroenterology. 2008. PMID 18061177.
13. 13

    Kannengiesser K, et al. Melanocortin-derived tripeptide KPV has anti-inflammatory potential in murine models of inflammatory bowel disease. Inflamm Bowel Dis. 2008. PMID 18092346.
14. 14

    Viennois E, et al. Critical role of PepT1 in promoting colitis-associated cancer and therapeutic benefits of the anti-inflammatory PepT1-mediated tripeptide KPV. Cell Mol Gastroenterol Hepatol. 2016. PMID 27458604.
15. 15

    Bonfiglio V, et al. Effects of the COOH-terminal tripeptide alpha-MSH(11-13) on corneal epithelial wound healing: role of nitric oxide. Exp Eye Res. 2006. PMID 16965771.
16. 16

    Schaible EV, et al. Single administration of tripeptide alpha-MSH(11-13) attenuates brain damage by reduced inflammation and apoptosis after experimental traumatic brain injury in mice. PLoS One. 2013. PMID 23940690.
17. 17

    An SH, et al. KPV attenuates adipogenesis and lipid metabolism through modulation of ROS-mediated AKT/mTORC1/PPARgamma signaling. Tissue Cell. 2026. PMID 42585803.
18. 18

    Sung J, et al. Lysine-Proline-Valine peptide mitigates fine dust-induced keratinocyte apoptosis and inflammation. Tissue Cell. 2025. PMID 40073467.
19. 19

    Hiltz ME, Catania A, Lipton JM. Alpha-MSH peptides inhibit acute inflammation induced in mice by rIL-1 beta, rIL-6, rTNF-alpha and endogenous pyrogen but not that caused by LTB4, PAF and rIL-8. Cytokine. 1992. PMID 1325196.
20. 20

    Uehara Y, et al. Carboxyl-terminal tripeptide of alpha-melanocyte-stimulating hormone antagonizes interleukin-1-induced anorexia. Eur J Pharmacol. 1992. PMID 1330615.
21. 21

    Uehara Y, et al. The dipeptide Lys-Pro attenuates interleukin-1 beta-induced anorexia. Peptides. 1993. PMID 8387184.
22. 22

    Cutuli M, et al. Antimicrobial effects of alpha-MSH peptides. J Leukoc Biol. 2000. PMID 10670585.
23. 23

    Rauch I. Anti-Candida activity of alpha-melanocyte-stimulating hormone (alpha-MSH) peptides. J Leukoc Biol. 2009;85(3):371-2, author reply 373. PMID 19092131.
24. 24

    Songok AC, et al. Structural modification of the tripeptide KPV by reductive "glycoalkylation" of the lysine residue. PLoS One. 2018. PMID 29953505.
25. 25

    Singh M, Mukhopadhyay K. C-terminal amino acids of alpha-melanocyte-stimulating hormone are requisite for its antibacterial activity against Staphylococcus aureus. Antimicrob Agents Chemother. 2011. PMID 21282427.
26. 26

    Charnley M, et al. Anti-microbial action of melanocortin peptides and identification of a novel X-Pro-D/L-Val sequence in Gram-positive and Gram-negative bacteria. Peptides. 2008. PMID 18355945.
27. 27

    Catania A, et al. Melanocortin peptides inhibit production of proinflammatory cytokines in blood of HIV-infected patients. Peptides. 1998. PMID 9700761.
28. 28

    Kucharzik T, et al. Tripeptide K(D)PT is well tolerated in mild-to-moderate ulcerative colitis: results from a randomized multicenter study. Inflamm Bowel Dis. 2017. PMID 28092306.
29. 29

    Pawar K, et al. Transdermal iontophoretic delivery of lysine-proline-valine (KPV) peptide across microporated human skin. J Pharm Sci. 2017. PMID 28343991.
30. 30

    Böhm M, Luger T. Are melanocortin peptides future therapeutics for cutaneous wound healing? Exp Dermatol. 2019. PMID 30661264.