KPV peptide: what it is, how it is supplied

KPV is a peptide of three amino acids — lysine, proline and valine (Lys-Pro-Val) — written with the one-letter code that gives it its name: K, P, V. It is the last three residues of α-melanocyte-stimulating hormone (α-MSH), a 13-residue peptide; KPV is the C-terminal fragment, positions 11 to 13.

• Sequence: Lys-Pro-Val (KPV).
• Molecular weight: about 342.4 Da as the free peptide; research suppliers usually sell the acetate salt, and the certificate of analysis states which.
• Appearance: white to off-white lyophilized powder, hygroscopic.
• Parent molecule: α-MSH, of which KPV is a synthetic fragment — it is made by chemical synthesis, not extracted.

It is one of the shortest peptides sold by research suppliers, and one of the simplest to characterize: a single main peak on the HPLC chromatogram and one expected mass on the spectrum.

Research use only. Not for human or veterinary use.

Research suppliers offer KPV the same way they offer any short synthetic peptide: as a lyophilized powder in a sealed glass vial with a rubber septum and an aluminum crimp cap. The label states the compound name, the net quantity in milligrams, a lot number and the words "research use only".

Because KPV is small and inexpensive to synthesize, it also turns up in cosmetic formulations at a fraction of a percent. Those are a different object from a lyophilized vial with a lot number, and a listing that gives no mg quantity and no COA is one of them.

For a tripeptide, the certificate is short, and every field on it is easy to check:

• The laboratory's name and a verifiable test number. Independent labs (Janoshik is the reference for this market) publish each test under a number anyone can look up.
• The lot number — the same one printed on the vial.
• HPLC purity as a measured percentage with the chromatogram. For a three-residue peptide, the main peak should dominate the trace; a chromatogram with several peaks of similar height is a red flag.
• Mass confirmation by mass spectrometry: an observed mass near 342 Da (free peptide) — a different number means a different compound.
• The test date and a photograph of the tested vial wearing the supplier's own label.

The full reading guide, with what an edited or re-used certificate looks like, is in how to read a peptide COA.

KPV follows the general rule for lyophilized peptides: cold, dark and dry.

• Temperature: −20 °C for long-term storage; a refrigerator (2–8 °C) for short periods.
• Light and moisture: keep the vial sealed and in its box; let a cold vial reach room temperature before it leaves its bag so no condensation forms on the glass.
• Shelf life: suppliers typically state 24 months for a sealed vial stored as above; the date on the label governs.

Ambient shipping for a few days does not degrade the sealed powder. The rules, compound by compound, are in lyophilized peptides: storage and shelf life.

"KPV peptides" returns cosmetic brands, marketplace listings and a handful of research suppliers. Five questions sort them:

1. Is there a batch COA from a named independent laboratory, verifiable on the lab's site?
2. Does the COA show the supplier's own label on the tested vial, and a mass near 342 Da?
3. Is the quantity stated in mg, with a lot number printed on the vial?
4. Does the supplier ship domestically, tracked, in a few days?
5. Does the product page describe the reagent only — composition, purity documentation, storage — with "research use only" stated plainly?

The wider checklist — payment, packaging, what to do if a parcel is stopped — is in where to buy research peptides in the US. The copper tripeptide GHK-Cu, another three-residue reagent, is described in the GHK-Cu buying guide.

KPV is not in the catalog yet. Leave an email below to be told the day it is listed — one email, no newsletter.

When it is listed, it will be supplied like every other compound in the catalog: a sealed, labeled vial from a tested lot, with the batch COA published on the product page.