KPV

01 · What it is

Most of the recent research on KPV is not about whether it works. It is about how to get it where it needs to go.

KPV is Lys-Pro-Val, the C-terminal tripeptide of α-melanocyte-stimulating hormone — α-MSH(11-13) ^3,10. It is the smallest sequence reported to prevent inflammation ⁴, and most of the anti-inflammatory activity of the parent hormone has been attributed to this terminal fragment ⁵. Three amino acids, from a hormone with thirteen.

The delivery problem is the field’s central preoccupation, and it is informative. Since roughly 2017 the literature has been dominated by engineering: hyaluronic-acid-functionalised nanoparticles for oral targeting ¹⁰, transdermal iontophoresis across microporated human skin ¹¹, a mucoadhesive hydrogel for oral mucositis ¹⁴, a self-cross-linked hydrogel for colitis in rats ¹³, a double-network hydrogel to restore gut mucosal barrier ¹⁵, and self-assembling carrier-free nanodrugs pairing KPV with rapamycin ¹⁶.

A 2026 study makes the reason explicit. A self-immolative conjugate designed to survive the gastrointestinal tract achieved 3.8-fold greater colonic accumulation than free KPV, with enhanced efficacy at a twenty-fold lower dose ¹⁷.

Free KPV, in other words, needed twenty times the dose to do less. That is the clearest published statement of what the plain peptide does on its own, and it comes from a paper trying to improve on it.

The route into cells is a transporter, not a melanocortin receptor. KPV’s anti-inflammatory action in the intestine is described as PepT1-mediated ⁸ — PepT1 being the human intestinal peptide transporter, expressed at low levels in the healthy colon and upregulated in inflammatory bowel disease ^8,9. Whether the tripeptides operate through MC1R or cyclic AMP was posed as an open question in 2004 ⁴ and this guide did not locate a paper that settles it.

A compound that enters through a transporter upregulated by the disease it treats is an elegant piece of biology. It also means the delivery route is inseparable from the effect.

No human trial of KPV was located. The only human tissue in this file is excised skin used to test an iontophoretic delivery method ¹¹.

02 · Evidence at a glance

Evidence grade

Preclinical — no human trial located

What it is

Lys-Pro-Val, the C-terminal tripeptide of α-MSH, α-MSH(11-13) ^3,10

Status within the parent hormone

The smallest sequence reported to prevent inflammation ⁴; most α-MSH anti-inflammatory activity is attributed to it ⁵

Proposed route into cells

PepT1, the intestinal peptide transporter ⁸ — upregulated in inflammatory bowel disease ^8,9

Receptor mechanism

Unresolved. Whether it acts via MC1R or cyclic AMP was an open question in 2004 ⁴ and no paper located here settles it

Animal models with reported benefit

Crystal-induced peritonitis ³; murine IBD ⁶; TNBS colitis in rats ^13,15; chemotherapy-induced oral mucositis ¹⁴; vascular calcification ¹⁶

Dominant research activity since 2017

Drug delivery engineering ^{9,10,11,13,14,15,16,17}

What that engineering reveals

A conjugate achieved 3.8× the colonic accumulation of free KPV and greater efficacy at a 20-fold lower dose ¹⁷

Topical delivery

Required iontophoresis across microporated human skin ¹¹

Human trials

None located

Human safety data

None

Published toxicology

None located

US regulatory status

Not an approved drug; not a lawful dietary supplement ingredient

Noted in doping literature

Yes — appears in a 2026 review of peptide use in sport ¹⁸

03 · Mechanism of action

A fragment that kept the activity

α-MSH is a potent anti-inflammatory mediator whose key action is inhibition of NF-κB ¹, present in barrier organs such as gut and skin, where it may form part of innate host defence ². When the molecule was dissected, the anti-inflammatory activity was found to sit largely in the C-terminal tripeptide ^5,7, and KPV was characterised in a model of crystal-induced peritonitis alongside other MSH peptides ³.

Finding that a three-residue fragment carries most of a hormone’s anti-inflammatory effect is a real result, and it is why this compound exists. The unanswered question is what the fragment binds.

The receptor question was asked and, in this file, never answered

In 2004 a study of α-MSH, MSH(11-13) and ACTH signalling in human keratinocytes stated plainly that the C-terminal tripeptides of α-MSH are the smallest minimal sequences reported to prevent inflammation but that it was not known whether they operate via MC1R or cyclic AMP, and used melanocortin-receptor-transfected Chinese hamster ovary cells to investigate ⁴.

Twenty-two years later, this guide could not locate a paper establishing the answer. A compound described everywhere as melanocortin-derived does not, on the evidence found here, have an established melanocortin receptor mechanism.

The transporter is the better-evidenced route

In the intestine the relevant mechanism is transport rather than receptor binding. PepT1 is expressed at low levels in the healthy colon and upregulated during inflammatory bowel disease, and KPV is described as the anti-inflammatory PepT1-mediated tripeptide in work examining PepT1’s role in colitis-associated cancer ⁸. PepT1 overexpression in the colonic epithelium of chronic ulcerative colitis has been exploited separately to build a targeted fluorescent probe ⁹.

This is the most satisfying mechanistic account in the guide: a tripeptide taken up by a peptide transporter that the disease itself switches on, delivering the compound preferentially to inflamed tissue. It is also specific to the gut, and says nothing about what happens elsewhere.

Structure–activity work is sparse

One study modified the tripeptide by reductive glycoalkylation of the lysine residue, applying the chemistry to H-KPV-NH2 ¹².

Almost the only medicinal chemistry on the molecule in this file. For a three-residue peptide with twenty-five years of interest behind it, that is very little.

04 · Key research findings

The parent hormone, 2000. Reviews establishing α-MSH as a neuroimmunomodulatory peptide acting through melanocortin receptors with NF-κB inhibition as the key anti-inflammatory step ¹, and as a possible component of innate host defence in gut and skin ².

Dissection of the fragment, 2003. Analysis of the anti-inflammatory effects of α-MSH(11-13) — KPV — against other MSH peptides in a model of crystal-induced peritonitis ³.

The receptor question, 2004. Signalling of α-MSH, MSH(11-13) and ACTH in human keratinocytes, explicitly framed around whether the C-terminal tripeptides act via MC1R or cyclic AMP ⁴.

Attribution to the C-terminus, 2007 and 2010. Reviews concluding that most of the anti-inflammatory activities of α-MSH can be attributed to its C-terminal sequence ⁵, and examining the effects of α-MSH-related tripeptides beyond the pharmacophore ⁷.

Inflammatory bowel disease models, 2008. KPV reported to have anti-inflammatory potential in murine models of inflammatory bowel disease, following earlier work on α-MSH in dextran sodium sulfate colitis ⁶.

PepT1 and colitis-associated cancer, 2016. Work establishing PepT1’s role in mouse colitis and examining the therapeutic benefit of PepT1-mediated KPV in a murine model of colitis-associated cancer ⁸.

The paper that ties the compound to a specific transport mechanism, and the strongest mechanistic result in the file.

The delivery programme, 2017–2026. A fluorescent probe exploiting PepT1 overexpression to distinguish chronic from acute ulcerative colitis ⁹; hyaluronic-acid-functionalised nanoparticles for orally targeted KPV in ulcerative colitis ¹⁰; transdermal iontophoretic delivery across microporated human skin ¹¹; a self-cross-linked cysteamine-grafted γ-polyglutamic acid hydrogel stabilising KPV for TNBS-induced colitis in rats, in which the stability of KPV in the hydrogel was the explicit object ¹³; an in situ mucoadhesive hydrogel for chemotherapy-induced oral mucositis, with antibacterial effect on MRSA-infected gingival ulcers ¹⁴; a KPV-binding double-network hydrogel restoring gut mucosal barrier, where the effect on TNBS colitis was significantly improved by the delivery system over intracolonic KPV alone ¹⁵; and carrier-free nanodrugs self-assembled from KPV and rapamycin for vascular calcification ¹⁶.

Nine years, at least seven distinct delivery platforms, and the recurring finding inside them is that the formulation improves on the free peptide. Read as a body, this literature is a sustained statement that plain KPV is difficult to deliver.

The 2026 conjugate, and the number that matters. Inflammation-triggered self-immolative conjugates designed to overcome gastrointestinal barriers for oral peptide delivery. In colitis mice, the KPV-based conjugate achieved 3.8-fold greater colonic accumulation than free KPV, with enhanced efficacy at a twenty-fold lower dose ¹⁷.

This is the single most useful figure in the guide. It quantifies the gap between the engineered form and the plain peptide, and it was published by people whose interest was in closing that gap rather than in disparaging KPV.

Appearance in doping literature, 2026. A critical review of peptide and peptide-analogue use in recreational and professional sport and bodybuilding, in which KPV appears among the compounds discussed ¹⁸.

Relevant to how the compound circulates, and not evidence of anything pharmacological.

05 · Evidence overview

06 · Safety profile

Human data. None. No published study has administered KPV to a person. The only human material in this file is excised skin used to characterise an iontophoretic delivery method ¹¹.

Animal data. No dedicated toxicology study was located. Safety information is incidental to efficacy work across peritonitis ³, murine IBD ⁶, rat TNBS colitis ^13,15, oral mucositis ¹⁴ and vascular calcification ¹⁶ models, none of which reports adverse findings in its abstract. That is not a safety assessment.

What is genuinely unknown. Everything required before human exposure: pharmacokinetics, dose-finding, repeat-dose toxicology, genotoxicity, carcinogenicity, reproductive toxicity.

Three gaps deserve specific naming. What the compound binds — the MC1R-versus-cAMP question posed in 2004 ⁴ remains open here, which means the off-target profile cannot be reasoned about from the mechanism. What systemic exposure does — the best-characterised mechanism is a gut transporter ⁸, and the entire delivery literature exists to concentrate the peptide in specific tissue ^10,13,15,17; nothing in this file describes what happens when it is distributed systemically instead. And what dose means for this compound, given that the same effect required a twenty-fold difference in dose depending on formulation ¹⁷ — a compound whose effective dose varies that much with delivery has no dose that can be discussed independently of how it is given.

Nothing is published on the identity or purity of any material sold under this name.

07 · US regulatory status

Current as of 7 September 2026. KPV is not an approved drug in the United States, is not a controlled substance, and is not a lawful dietary supplement ingredient. No marketing authorisation in any jurisdiction was identified for this guide.

Under the World Anti-Doping Code, KPV does not appear as a named prohibited substance in the classes reviewed here, though it is discussed in a 2026 review of peptide use in sport ¹⁸. Competitors should consult the current Prohibited List directly rather than rely on secondary summaries, including this one.

08 · Limitations of the evidence

1. The free peptide performs measurably worse than its formulated versions, and one paper puts a number on it. Twenty-fold higher dose for less effect, and 3.8-fold lower accumulation at the target tissue ¹⁷. Every animal result reported here should be read against the question of how the compound was delivered, because the delivery is doing a substantial part of the work.
2. No human has been given KPV in any published study. Not a trial, not a pharmacokinetic study, not a safety cohort. The single human element in the file is excised skin in a delivery experiment ¹¹.
3. The receptor mechanism is unresolved after two decades. The question of whether the C-terminal tripeptides act through MC1R or cyclic AMP was posed explicitly in 2004 ⁴; no paper located here answers it. Describing KPV as melanocortin-derived is accurate about its origin and says nothing established about its target.
4. The best-evidenced mechanism is organ-specific. PepT1-mediated uptake ⁸ explains action in an inflamed gut and does not transfer to skin, joint or systemic use.
5. Animal-to-human translation is unattempted, and the models are acute chemical injuries. DSS and TNBS colitis, crystal-induced peritonitis and chemotherapy-induced mucositis ^3,6,13,14,15 are induced-injury models whose record of predicting human inflammatory-disease outcomes is poor across the whole field.
6. The literature has shifted from pharmacology to formulation. Since 2017 the substantial output concerns delivery platforms ^{9,10,11,13,14,15,16,17} rather than whether or how the molecule works. A field that stops asking the first question has usually decided the answer is settled or uninteresting, and nothing here establishes which.
7. Structure–activity data are almost absent. One glycoalkylation study ¹². For a three-residue peptide, that is a remarkably thin basis for understanding what matters in the molecule.
8. Publication bias cannot be assessed. No registry exists for animal work, and a literature composed largely of successful formulation papers is exactly the shape that positive-results reporting produces.
9. No toxicology exists. An absence, not a quality caveat.
10. This guide has read abstracts, not full texts, for every source cited, including the 2026 conjugate paper whose dose comparison the guide leans on.
11. Nothing is known about material sold under this name. No published analysis has examined the identity or purity of any KPV-labelled product.

09 · References

1. Ichiyama T, Sato S, Okada K, Catania A, Lipton JM. The neuroimmunomodulatory peptide α-MSH. Ann N Y Acad Sci. 2000;917:221–226. Review.

   PMID 11268347 ↗

2. Catania A, Cutuli M, Garofalo L, Carlin A, Airaghi L, Barcellini W, Lipton JM. The neuropeptide α-MSH in host defense. Ann N Y Acad Sci. 2000;917:227–231. Review.

   PMID 11268348 ↗

3. Getting SJ, Schiöth HB, Perretti M. Dissection of the anti-inflammatory effect of the core and C-terminal (KPV) α-melanocyte-stimulating hormone peptides. J Pharmacol Exp Ther. 2003 Aug;306(2):631–637.

   PMID 12750433 ↗

4. Elliott RJ, Szabo M, Wagner MJ, Kemp EH, MacNeil S, Haycock JW. α-Melanocyte-stimulating hormone, MSH 11-13 KPV and adrenocorticotropic hormone signalling in human keratinocyte cells. J Invest Dermatol. 2004 Apr;122(4):1010–1019.

   PMID 15102092 ↗

5. Luger TA, Brzoska T. α-MSH related peptides: a new class of anti-inflammatory and immunomodulating drugs. Ann Rheum Dis. 2007 Nov;66 Suppl 3:iii52–iii55.

   PMID 17934097 ↗

6. Kannengiesser K, Maaser C, Heidemann J, Luegering A, Ross M, Brzoska T, Bohm M, Luger TA, Domschke W, Kucharzik T. Melanocortin-derived tripeptide KPV has anti-inflammatory potential in murine models of inflammatory bowel disease. Inflamm Bowel Dis. 2008 Mar;14(3):324–331.

   PMID 18092346 ↗

7. Brzoska T, Böhm M, Lügering A, Loser K, Luger TA. Terminal signal: anti-inflammatory effects of α-melanocyte-stimulating hormone related peptides beyond the pharmacophore. Adv Exp Med Biol. 2010;681:107–116. Review.

   PMID 21222263 ↗

8. Viennois E, Ingersoll SA, Ayyadurai S, Zhao Y, Wang L, Zhang M, Han MK, Garg P, Xiao B, Merlin D. Critical role of PepT1 in promoting colitis-associated cancer and therapeutic benefits of the anti-inflammatory PepT1-mediated tripeptide KPV in a murine model. Cell Mol Gastroenterol Hepatol. 2016 May;2(3):340–357.

   PMID 27458604 ↗

9. Zeng M, Shao A, Li H, Tang Y, Li Q, Guo Z, Wu C, Cheng Y, Tian H, Zhu WH. Peptide receptor-targeted fluorescent probe: visualization and discrimination between chronic and acute ulcerative colitis. ACS Appl Mater Interfaces. 2017 Apr 19;9(15):13029–13036.

   PMID 28349696 ↗

10. Xiao B, Xu Z, Viennois E, Zhang Y, Zhang Z, Zhang M, Han MK, Kang Y, Merlin D. Orally targeted delivery of tripeptide KPV via hyaluronic acid-functionalized nanoparticles efficiently alleviates ulcerative colitis. Mol Ther. 2017 Jul 5;25(7):1628–1640.

    PMID 28143741 ↗

11. Pawar K, Kolli CS, Rangari VK, Babu RJ. Transdermal iontophoretic delivery of lysine-proline-valine (KPV) peptide across microporated human skin. J Pharm Sci. 2017 Jul;106(7):1814–1820.

    PMID 28343991 ↗

12. Songok AC, Panta P, Doerrler WT, Macnaughtan MA, Taylor CM. Structural modification of the tripeptide KPV by reductive “glycoalkylation” of the lysine residue. PLoS One. 2018 Jun 28;13(6):e0199686.

    PMID 29953505 ↗

13. Sun J, Xue P, Liu J, Huang L, Lin G, Ran K, Yang J, Lu C, Zhao YZ, Xu HL. Self-cross-linked hydrogel of cysteamine-grafted γ-polyglutamic acid stabilized tripeptide KPV for alleviating TNBS-induced ulcerative colitis in rats. ACS Biomater Sci Eng. 2021 Oct 11;7(10):4859–4869.

    PMID 34547895 ↗

14. Shao W, Chen R, Lin G, Ran K, Zhang Y, Yang J, Pan H, Shangguan J, Zhao Y, Xu H. In situ mucoadhesive hydrogel capturing tripeptide KPV: the anti-inflammatory, antibacterial and repairing effect on chemotherapy-induced oral mucositis. Biomater Sci. 2021 Dec 21;10(1):227–242.

    PMID 34846053 ↗

15. Zhao Y, Xue P, Lin G, Tong M, Yang J, Zhang Y, Ran K, Zhuge D, Yao Q, Xu H. A KPV-binding double-network hydrogel restores gut mucosal barrier in an inflamed colon. Acta Biomater. 2022 Apr 15;143:233–252.

    PMID 35245681 ↗

16. Zhang L, Li D, Aierken Y, Zhang J, Liu Z, Lin Z, Jiang L, Li Q, Wu Y, Liu Y. KPV and RAPA self-assembled into carrier-free nanodrugs for vascular calcification therapy. Adv Healthc Mater. 2024 Dec;13(32):e2402320.

    PMID 39252648 ↗

17. Cheng J, Wu P, Li C, Han Y, Sun M, Dou Y, Chen S, Zhang J. Inflammation-triggered self-immolative conjugates enable oral peptide delivery by overcoming gastrointestinal barriers. Sci Adv. 2026 Jan 16;12(3):eaea2989.

    PMID 41533788 ↗

18. Coutinho LFD, de Oliveira Neves LF, Camilo RP. A new era of doping? Use of peptide and peptide-analog drugs in recreational and professional sport and bodybuilding: a critical review. J Sports Med Phys Fitness. 2026 Jul;66(7):880–885. Review.

    PMID 41880199 ↗