What is KPV's PubChem record?

CID 125672, indexed as Lys-Pro-Val at 342.43 Da. Searching 'KPV' returns an unrelated organic acid at 192.21 Da.

Where does KPV come from?

It is the C-terminal tripeptide of alpha-MSH, isolated to keep the anti-inflammatory activity without the pigmentation.

Can it be quantified at 280 nm?

No. It contains no aromatic residue, so there is no usable absorbance there.

KLOW (Blend)

KPV: The Component With a Different Parent

JMWritten & reviewed by Jack Muncaster · Founder, UK PeptidesLast reviewed 2026-08-234 cited sources

KPV is Lys-Pro-Val at 342.43 Da, the C-terminal tripeptide of alpha-melanocyte-stimulating hormone. Its PubChem record is indexed as Lys-Pro-Val at CID 125672 — searching the three-letter name returns an unrelated organic acid.

Key facts

Sequence: Lys-Pro-Val
Molecular weight: 342.43 Da
Formula: C16H30N4O4
PubChem CID: 125672 (as Lys-Pro-Val)
Searching 'KPV' returns: An unrelated acid, 192.21 Da
Parent: alpha-MSH, 1,664.9 Da

Where it comes from

Alpha-MSH is a thirteen-residue hormone that drives pigmentation through melanocortin receptors and separately carries anti-inflammatory activity at its C-terminal end. KPV is those last three residues synthesised alone — the anti-inflammatory portion isolated from the pigmentation-driving core.

The identifier problem

Searching PubChem for KPV returns CID 13294447, 2-oxo-5-phenylpentanoic acid at 192.21 Da. That is not a peptide and has no relation to alpha-MSH. The tripeptide is indexed as Lys-Pro-Val at CID 125672 — a 150 Da difference that is unmistakable once both records are open and invisible if only one is consulted.

Research material referenced

KLOW 80mg — third-party HPLC tested

View — £69.99

Why three residues can do anything

A tripeptide has no capacity for secondary structure, so whatever activity it has comes from side-chain chemistry and the local geometry proline imposes. Its reported effects are described in terms of NF-kappaB signalling rather than receptor binding — and at 342.43 Da it is small enough for intracellular access that its 1,665 Da parent could not have.

What it contributes chemically to the blend

No cysteine, no methionine, no aromatic residue. That means no substrate for copper-catalysed oxidation, no +16 Da satellite to expect, and no usable absorbance at 280 nm. It is chemically the most inert component and analytically among the hardest to see.

And the family relationship

MT-2, in a separate category of this catalogue, is also derived from alpha-MSH — but built around the receptor-binding core KPV discards. Two products from one hormone, pursuing its two separable functions in opposite directions.

Extended research context

The KLOW (Blend) deep dive

Deep dive: a fourfold size range in one cake, and what partial dissolution hides

KLOW's components run from KPV at 342.43 daltons to BPC-157 at 1419.5 - a fourfold span, and the widest of any product in this catalogue. Solubility depends on size, charge distribution and hydrophobicity, and these four differ in all three, so a co-lyophilised cake containing all of them releases its components in sequence rather than together. The hazard follows directly and is easy to miss: a cake that looks partly dissolved is not uniformly partly dissolved. The smallest component may be entirely in solution while the largest has barely started. Draw from the vial at that moment and the sample is enriched in the fast components and depleted in the slow ones - a composition error with no visible sign at all, since the liquid looks like liquid. The instinctive response to visible solid makes it worse: shaking creates air-liquid interfaces, which is exactly where peptides unfold and then aggregate irreversibly. The correct response is diluent down the vial wall, gentle swirling, and more patience than a single peptide or even a three-component blend requires. There is a second asymmetry on top. Small peptides adsorb to glass and plastic more readily than large ones, so KPV is the component most likely to be lost to container walls at low concentration - a silent shift in the effective ratio that no certificate figure accounts for.

Deep dive: the cleanest possible comparison, which still cannot be run

KLOW is a strict superset of GLOW - the same three components plus KPV, at 80 mg against 70 mg. Product comparisons rarely have this structure. There is nothing in GLOW that KLOW lacks, so the difference between them reduces to a single question rather than a balance of trade-offs, and in principle comparing the two would isolate exactly what KPV contributes. In practice it cannot be done. The 10 mg difference in total might be 10 mg of added KPV with the other three unchanged, or it might be a redistribution across all four; both are consistent with the published figures, and neither product states its split. So any difference observed between the two could be KPV, or it could be a changed concentration of GHK-Cu, BPC-157 or TB-500. The experiment that the product pairing seems designed to permit is precisely the one the missing information forbids. This is the fixed-ratio limitation in its sharpest form: not that the format is unhelpful in general, but that it withholds the one number that would make the most natural question answerable.

Deep dive: two products from one hormone, in categories that never mention each other

KPV is the C-terminal tripeptide of alpha-melanocyte-stimulating hormone, isolated because that hormone does two functionally separable things - pigmentation through melanocortin receptors, and anti-inflammatory activity localised to its C-terminal end. KPV keeps the second and discards the first. Now look elsewhere in this catalogue: MT-2 is also an alpha-MSH derivative, and it is built around the melanocortin-receptor-binding core that KPV was specifically designed to leave behind. Two products, one parent hormone, opposite halves of its function, sitting in entirely separate product categories with nothing in either listing to indicate they are related. The size difference tracks the design logic. KPV at 342.43 daltons is three residues with no modifications, because an effect running through diffuse intracellular signalling can survive extreme truncation. MT-2 at 1024.2 daltons is seven residues plus a lactam bridge, a D-amino acid and two capped termini, because receptor engagement requires enough structure to present a specific surface. What a fragment needs to be depends entirely on what the retained function requires, and these two are as clean an illustration of that as this catalogue contains.

Research applications

▸Multi-component connective tissue research protocols
▸Comparative work on three-component versus four-component combinations
▸Co-lyophilisation and multi-component dissolution methodology
▸Copper peptide compatibility studies
▸Surface adsorption behaviour across a wide molecular size range
▸Anti-inflammatory and matrix pathway research

Handling checklist

✓Verify KPV as Lys-Pro-Val at 342.43 Da, CID 125672 - never by searching 'KPV'
✓Verify GHK-Cu against 402.92 Da (CID 71587328), not 340.38 for free GHK
✓Verify TB-500 against 889.0 Da, not 4.9 kDa for thymosin beta-4
✓Verify BPC-157 against 1419.5 Da
✓Expect four separate certifications - a single combined purity figure is a category error
✓Allow more dissolution time than a three-component blend; do not draw before it completes
✓Use low-binding consumables - KPV is the component most lost to surfaces
✓Store lyophilised, cold, dry and dark; the copper complex governs light protection

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Drawing from a partly dissolved four-component cake

Fix: Components dissolve in sequence across a fourfold size range. An early sample is enriched in fast components and depleted in slow ones, with no visible sign.

✗ Verifying the KPV component by searching 'KPV' in PubChem

Fix: That returns 2-oxo-5-phenylpentanoic acid at 192.21 Da, an unrelated compound. Search Lys-Pro-Val for CID 125672.

✗ Assuming the 10mg difference from GLOW is 10mg of KPV

Fix: Not stated. It could be added KPV with the others unchanged, or a redistribution across all four.

✗ Treating four component literatures as evidence about the blend

Fix: No published work addresses this combination or any subset of it. Summing separate literatures produces no evidence about a mixture.

✗ Adding a chelator because the blend contains copper

Fix: Unnecessary. None of the four components contains cysteine or methionine, so copper-catalysed oxidation has no substrate here.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Frequently asked questions

What is KPV's PubChem record?: CID 125672, indexed as Lys-Pro-Val at 342.43 Da. Searching 'KPV' returns an unrelated organic acid at 192.21 Da.
Where does KPV come from?: It is the C-terminal tripeptide of alpha-MSH, isolated to keep the anti-inflammatory activity without the pigmentation.
Can it be quantified at 280 nm?: No. It contains no aromatic residue, so there is no usable absorbance there.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

Written and reviewed by

Jack Muncaster · Founder, UK Peptides

Jack founded UK Peptides in Manchester after repeatedly receiving research compounds with missing or recycled paperwork. He is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate.

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