KPV, explained: three amino acids off the end of a hormone

KPV is the answer to a question researchers often ask about a hormone: is the whole thing necessary, or does a piece of it do the interesting part on its own?

What it is

Alpha-melanocyte-stimulating hormone, alpha-MSH, is a 13-amino-acid peptide cleaved from pro-opiomelanocortin. It is best known for driving pigmentation through the melanocortin-1 receptor, and it has a long-documented second character as a modulator of inflammatory signalling.

KPV is residues 11 to 13 of that hormone: lysine, proline, valine. Three amino acids, molecular mass about 342 Da. For scale, that is roughly a fourteenth the size of an incretin analogue and almost exactly the size of GHK, the other very small peptide in this catalogue.

Why the fragment and not the whole hormone

This is the question worth answering, and the answer is structural.

The pigmentation activity of alpha-MSH lives in a four-residue core near the middle of the molecule, histidine-phenylalanine-arginine-tryptophan, usually written HFRW. That core is what the melanocortin receptors recognise. It sits at positions 6 to 9.

KPV is positions 11 to 13. It does not contain the HFRW core, so it does not engage the melanocortin receptors the way the parent hormone does, and it is not a pigmentation agent. Researchers interested in the anti-inflammatory side of alpha-MSH without its receptor-mediated pigmentation activity have therefore studied the tail fragment on its own. That is the entire rationale for KPV existing as a separate research compound.

What has been studied

Two strands are worth naming.

Inflammatory signalling. Brzoska and colleagues reviewed alpha-MSH and its fragments in Endocrine Reviews in 2008, covering in-vitro and in-vivo work on inflammatory pathways. Much of the KPV-specific literature reports effects on NF-kappa-B signalling in cultured cells.

Transport. Dalmasso and colleagues reported in Gastroenterology in 2008 that KPV is taken up by PepT1, an intestinal di- and tripeptide transporter, in models of intestinal inflammation. This matters mechanistically: most peptides do not survive the gut, and a molecule small enough to ride an existing peptide transporter is in a different position from a 39-residue analogue. The general problem is covered here.

The literature is largely pre-clinical. KPV has not been through a clinical programme and we do not characterise it as having established human effects.

Regulatory status

KPV has no marketing authorisation as a medicine anywhere. In the UK it may lawfully be bought, sold and held for laboratory research, and may not be sold or advertised for human or veterinary use. What that permission covers, and where sellers cross the line.

It is not currently on the WADA Prohibited List, unlike the GHRH analogues. Which peptides are prohibited.

What matters for research supply

A tripeptide is cheap and easy to synthesise, which cuts both ways: there is little economic reason to adulterate it, and equally little friction for anyone selling material that was never properly characterised.

1. Identity. The observed mass should be around 342 Da. For a molecule this small, mass spectrometry is a strong identity check. How to read a certificate.
2. Purity, with the method stated. What the figure measures.
3. Quantity, which is a separate number. Purity is not quantity.
4. Batch traceability through certificate, carton and batch lookup.
5. Storage — 2 to 8°C, dark, not frozen.

How Biovanta supplies it

KPV 10 mg comes in a factory-sealed pre-filled pen with sterile needles and prep swabs, manufactured in Switzerland and dispatched from the UK, with an independent Janoshik report per batch and a key you can verify on the laboratory's own site from the testing page. Supplied strictly for in-vitro laboratory research.