What is KPV?

Three letters, three amino acids

KPV is not an abbreviation of a project, a company or a trade name. The letters are the single-letter codes for lysine, proline and valine — the substance is named after its own sequence, written out as Lys-Pro-Val. Research papers often call the same molecule α-MSH(11–13), because those three residues occupy positions 11, 12 and 13 of α-melanocyte-stimulating hormone.

Being named by sequence is itself a marker of where a substance sits. Drug substances that go through development acquire a nonproprietary name — afamelanotide, setmelanotide, timbetasin. KPV has neither a United States Adopted Name nor an International Nonproprietary Name, so there is nothing to call it except its own letters. That absence is not cosmetic: it was one of the specific objections FDA review staff raised in July 2026.

Where it comes from

The body makes a large precursor protein called proopiomelanocortin, or POMC, and cuts it into several smaller hormones — among them ACTH, β-endorphin and α-MSH. α-MSH is thirteen amino acids long and does two things that can be separated: it drives pigmentation through melanocortin receptors, and it damps down inflammation.

That separation is the whole reason the fragment gets studied on its own. A 2021 review in Pharmaceuticals describes the C-terminal tripeptides of α-MSH as carrying anti-inflammatory properties “with no pigmentary effects”. Researchers interested in the second effect without the first work with the tail rather than the hormone.

What KPV is not

Most of the confusion around this substance comes from what it gets grouped with rather than what it is.

Not α-MSH. The hormone is thirteen residues and binds melanocortin receptors; KPV is three residues and its mechanism is disputed — reported variously through MC3R, through the PepT1 oligopeptide transporter in the gut, and “probably” through MC1R in the brain. Evidence about the hormone is not evidence about the fragment.

Not a growth factor. KPV is sold beside BPC-157 and TB-500 and described in the same language of recovery and repair, but those are marketed on tissue growth and blood-vessel formation. The published KPV work is about inflammatory signalling. The three keep company on vendor menus, not in the literature.

Not a melanotan. Melanotan II comes from the same hormone family and is sold for tanning; it is on the FDA advisory committee’s agenda for the second meeting, due before the end of February 2027. KPV is studied for the opposite property — the reason it is interesting is that it is reported not to pigment.

Not a single ingredient of a blend. KPV is the K in KLOW, a vial that also contains GHK-Cu, BPC-157 and TB-500. Those four substances sit at four different points in the FDA’s process, and mixing them into one vial does not give the mixture a status of its own.

Not one substance, as far as the FDA is concerned. KPV circulates as a free base and as an acetate salt, and the agency treats peptide salt forms as chemically distinct. When the advisory committee voted in July 2026 it voted on the two forms separately.

What has actually been studied

The published record runs through immortalized human bronchial epithelial cells, mice with experimentally induced colitis — often with the peptide packaged into nanoparticles to reach inflamed gut tissue — and corneal wound healing in rabbits. Two things are worth noticing straight away: there is no human trial in that list, and the routes are oral and topical, while the material sold on the gray market is largely injectable.

The full account of what that evidence does and does not support belongs on the approval question: Is KPV FDA-approved? goes through the three melanocortin drugs that are approved, why none of them is evidence about KPV, and what approval would require. For compounding and the 2026 regulatory position, see Is KPV legal in the US?, and for the framework both sit inside, our explainer on US peptide regulation.

Primary sources: Dinparastisaleh R, Mirsaeidi M, Pharmaceuticals 2021;14(1):45 (C-terminal α-MSH tripeptides; anti-inflammatory activity without pigmentary effects; experimental systems) · Tao Y-X et al., Front Endocrinol 2019;10:683 (α-MSH(11–13) nomenclature) · Front Pharmacol 2024;15:1442876 (PepT1-targeted KPV nanoparticles, murine colitis) · FDA Advisory Committee Calendar and Federal Register docket FDA-2025-N-6895 (PCAC, 23–24 July 2026; separate votes on free base and acetate forms) · FDA 503A interim bulk substances lists.