# KPV: Three Amino Acids, Zero Human Trials > KPV: Research Overview — peptideradar — A cited literature summary of KPV (Lys-Pro-Val), the anti-inflammatory C-terminal tripeptide of alpha-MSH — the PepT1 transport mechanism, the mouse colitis data, and the complete absence of published human clinical trials. **03 / EMERGING PIPELINE** The tail end of a human hormone, stripped of its pigmentary action and retaining its anti-inflammatory one — convincingly in cells, repeatedly in mice, and never yet in a published clinical trial. ## The short version KPV is about as small as a peptide gets: three amino acids, lysine-proline-valine. It is the last three residues of alpha-melanocyte-stimulating hormone, a hormone the body makes that both darkens skin and calms inflammation. Cut off this three-residue tail and the anti-inflammatory activity largely survives while the pigment-producing activity does not [17]. Most of the research is about the gut. KPV is carried directly into the cells lining the intestine by a transporter called PepT1, which normally ferries small peptides from digested food — and which is present at higher levels in inflamed intestinal tissue. Once inside, KPV dampens two of the main inflammatory signalling systems in the cell and reduces the output of inflammatory messengers [15]. In mice with chemically induced colitis, KPV consistently reduces disease severity [15][16]. What does not exist is a single published human clinical trial. There is no established human dose, no human safety data and no proof that any of the mouse results transfer. KPV is sold for laboratory research only. ## What it is KPV is the linear tripeptide L-lysyl-L-prolyl-L-valine, molecular formula C16H30N4O4, corresponding to residues 11 to 13 — the C-terminal sequence — of alpha-melanocyte-stimulating hormone. It appears in the literature under several names, including Lys-Pro-Val, alpha-MSH(11-13) and simply *the melanocortin tripeptide*. Its defining property in the published record is a separation of functions. Alpha-MSH is a potent anti-inflammatory hormone and also the principal driver of melanin production. A 2008 review in *Endocrine Reviews* covering alpha-MSH and its related tripeptides describes KPV as retaining broad anti-inflammatory activity — including suppression of NF-kB signalling and reduced pro-inflammatory cytokine production — while lacking the pigmentary action of the parent hormone, and catalogues protective effects for this tripeptide family across models of fever, dermatitis, vasculitis, fibrosis, ocular injury, gastrointestinal inflammation, brain and airway inflammation, arthritis and organ injury [17]. That breadth is the strongest argument for the molecule and, read carefully, also the strongest warning: it is a catalogue of animal and in vitro models, not of treated patients. KPV is not an approved drug or dietary supplement in any major jurisdiction. It is supplied by chemical vendors for laboratory research use only, and it is not specifically listed by name in anti-doping regulations — an absence that should not be mistaken for clearance. ## How it works — the proposed mechanism Two mechanisms carry most of the literature. The first is transport. KPV is taken up into intestinal epithelial cells through PepT1 (SLC15A1), the di- and tripeptide transporter, which is upregulated in inflamed intestinal tissue. That upregulation is the pharmacological hook the field keeps returning to: the sicker the tissue, the more efficiently it imports the peptide [15]. The second is signalling. Inside the cell, KPV at nanomolar concentrations reduces activation of NF-kB and the MAP kinases — two of the central inflammatory control systems — and lowers secretion of pro-inflammatory cytokines including IL-1beta and TNF-alpha [15]. Notably, this activity does not depend on the melanocortin-1 receptor: KPV retained its effect in MC1R-deficient mice, indicating an MC1R-independent route [16]. The practical obstacle is that KPV is a small, peptidase-labile tripeptide. Free KPV is degraded quickly, which is why a large share of recent research is not about the molecule at all but about *keeping it intact long enough to act* — hyaluronic-acid-functionalised nanoparticles, hydrogel carriers, PepT1-targeted co-assemblies [13][14]. A compound whose recent literature is dominated by formulation chemistry is a compound whose delivery problem is not yet solved. ## What the research actually shows *Transport and signalling, cells and mice.* The foundational 2008 study in *Gastroenterology* established PepT1-mediated uptake of KPV in human intestinal epithelial cell lines (Caco2-BBE and HT29-Cl.19A) and in Jurkat T cells, showed that nanomolar KPV reduced NF-kB and MAP-kinase activation and pro-inflammatory cytokine secretion, and reported that orally administered KPV reduced the severity of both DSS- and TNBS-induced colitis in C57BL/6 mice [15]. *Colitis, independent of the melanocortin receptor.* A companion 2008 study in *Inflammatory Bowel Disease* found KPV-treated mice in the DSS model recovered earlier and regained significantly more body weight, with reduced colonic inflammatory infiltrate and lower myeloperoxidase activity, and demonstrated that the effect persisted in MC1R-deficient animals [16]. *Targeted oral delivery.* A 2017 study in *Molecular Therapy* embedded hyaluronic-acid-functionalised KPV nanoparticles in a chitosan/alginate hydrogel for oral administration in DSS colitis mice. The targeted formulation prevented mucosal damage and downregulated TNF-alpha considerably more effectively than non-targeted delivery, accelerating mucosal healing [14]. *Combination nanodrug.* A 2024 study in *Frontiers in Pharmacology* co-assembled KPV with the immunosuppressant FK506 into a PepT1-targeted nanodrug and tested it in both acute (4% DSS) and chronic (2.5% DSS) colitis in C57 mice. The combination improved disease outcomes, restored tight-junction proteins and lowered inflammatory cytokines beyond either agent alone [13]. *Review-level synthesis.* The 2008 *Endocrine Reviews* survey places KPV within the wider alpha-MSH tripeptide family and across the range of inflammatory models in which these peptides have shown protective effects [17]. The pattern is consistent and it is entirely preclinical. Five sources, four experimental papers, one review, and not a single human participant among them. ## Cautions, gaps and what is missing This digest records no community-report layer for KPV and no corpus-level safety-caution set. As with any compound never tested in a controlled human trial, the absence of reported harms is an absence of data, not a finding of safety. The documented limitations: - **No published human clinical trials.** The entire efficacy literature is in vitro and animal work, chiefly murine colitis [13][14][15][16]. Human dosing, efficacy and safety are therefore unestablished — not merely uncertain at the margins, but absent. - **No validated human pharmacokinetics.** Free KPV is a small, peptidase-labile tripeptide with no measured human half-life or bioavailability. Much of the field's current effort is formulation work aimed precisely at that instability [13][14]. - **Marketing outruns the evidence.** KPV is promoted for gut health, skin and general anti-inflammatory use on the strength of a mechanistic and preclinical record. The literature supports a hypothesis worth testing, not a use worth adopting. - **It is not a tanning or pigmentation agent.** Although KPV derives from alpha-MSH, its defining feature in the literature is anti-inflammatory action *without* pigmentary effect, and it should not be conflated with melanocortin agonists used for pigmentation [17]. - **Secondary sources get the citations wrong.** Incorrect PubMed and DOI identifiers are common in web write-ups of KPV. The identifiers behind this page were re-verified against the primary indexes; anyone checking these claims should read the sources rather than the aggregators. - **Research-use status.** KPV is sold by chemical suppliers for laboratory research use only and is not an approved drug or dietary supplement anywhere. Material from unregulated suppliers carries no assurance of identity, purity or sterility. No human dose is recommended on this site, and for KPV there is no human study whose quantities could even be reported. ## Where it sits on the radar KPV is the earliest-stage compound on this desk. Its mechanism is well described, its preclinical results are consistent across independent groups and across two decades, and its clinical evidence base is empty [15][16][17]. The honest framing is that KPV looks like a plausible drug candidate that nobody has yet developed into a drug. Its most active research area is delivery chemistry rather than clinical testing [13][14], which is a reasonable proxy for how far the field itself judges the compound to be from human use. Consistency across mouse colitis models is meaningful evidence of biological activity; it is not evidence of therapeutic benefit in people, and the history of anti-inflammatory candidates that worked in DSS colitis and failed in patients is long. Compared with [retatrutide](/retatrutide) it is three tiers back, and compared with [MOTS-c](/mots-c) it lacks even an observational human cohort. The [comparison page](/compare) lays the three out together. --- peptideradar is an independent literature digest on unapproved research peptides that reports where the evidence stops rather than where the marketing starts — not a clinic, not a vendor, and not medical advice.