Your body makes a signalling molecule called alpha melanocyte stimulating hormone, a chain of 13 of the building blocks that proteins are made from, written out as SYSMEHFRWGKPV. KPV is the last three of those building blocks, lysine, proline and valine, and that is the whole compound. Short chains like this are called peptides. Almost every claim made for KPV borrows the reputation of the full 13 unit molecule it was cut from, and in 2003 one lab put the two side by side and the borrowing did not hold.
What it is supposed to do
The story sold with it is that it calms inflammation the way the parent molecule does. In 2003 three researchers put the parent and its fragments into the same immune cells, the ones that swallow germs whole, alongside a drug built to hit the same docking points. The parent and that drug both switched off two inflammation signals. KPV did nothing, not to those signals and not to the cells. The same team then asked whether KPV touches those docking points at all, by measuring the messenger a cell puts out when a docking point fires: the drug pushed it up, a blocker pushed it down, and KPV moved it neither way, so it was neither switching them on nor blocking them. In mice, KPV still calmed colon inflammation with those docking points blocked and in animals bred without a third one, and the authors concluded it was unlikely to be working through that receptor family at all. What does look real is in the gut. The lining of your intestine carries a transporter whose job is hauling two and three unit scraps of digested food into the cell, KPV is three units long, so it rides in on that. In mice bred without that transporter, the peptide did nothing at all. Take away the food door and the effect disappears.
What people take it for
It is sold three ways, as something to inject under the skin, as something to swallow, and as a cream for the skin, and the injected form is the one with the best marketing behind it. What the published research is actually about is calming inflammation in the gut of a rodent. The skin claims trace back to films laid on surgical wounds in diabetic mice, and the writer of the entry could not locate the paper being cited for them. Vendor pages also carry cycling patterns, 8 on and 8 off, or 5 on and 2 off, with no source behind them.
The dose question
What circulates
200 to 400 mcg a day injected, 250 mcg twice daily by mouth
What was studied
No human dose has ever been published
The only figure in the literature is 16 mcg/kg/day in mice, by feeding tube
There is nothing to compare against. Scaling that mouse figure the standard way lands near 90 mcg a day for an adult, which puts the oral convention five to ten times above the only number the literature can carry, and that number came from a mouse getting nanoparticles down a feeding tube. The injected convention sits above nothing at all, because nobody has published an injection of KPV in any species.
Reported because it is what people use. Nothing here recommends any amount.
How long it lasts
Nobody has measured this in a person. There are no published human figures for how KPV is absorbed or how long it lasts, by any route. Vendor pages say the half life is short and cite nothing for it.
Route studied
In rodents and in cells in a dish only, and every result came with a delivery vehicle. By mouth in the drinking water, down a tube into the stomach with the peptide wrapped in tiny particles, in polymer capsules built to open in the colon, and as gels put into the rectum, because a plain solution would not be absorbed that way. On skin, plain diffusion put no measurable amount into the deeper layers, and it took tiny needles punching holes through the surface to get it through. No human study exists by any route.
Route used
Injected under the skin, swallowed, or rubbed on the skin. No injection of KPV has been published in any species.
How to check you have the right molecule
Two different molecules are sold under this one name, and an ordinary lab report will not tell you which one you have. The version with a chemical cap on the tail end has the formula C16H31N5O3 and weighs 341.45, listed in the public chemical database PubChem under identifier 7019758. The version without that cap has the formula C16H30N4O4 and weighs 342.43, listed under identifier 125672. Those two weights sit just under one unit apart, and vendor pages do not say which form is in the vial, so the report is the only thing that will. The Food and Drug Administration paperwork covers both a free base and an acetate salt, so the name on the label settles nothing on its own. One further check is on paperwork rather than powder: there is no KPV trial on the United States government registry, so any trial number offered to you as support for a product is not a KPV trial.
The expensive mistake is buying the injected form on the strength of the parent molecule's research. The 2003 experiment put the fragment next to the parent, in the same cells, on the same day, and the fragment did nothing the parent did, and that paper still turns up in the opening paragraph of product pages cited as support. Of the three forms being sold, the injection has the best marketing and the worst evidence, which is none, in any species. What the published work shows is a local gut treatment for rodents that only works because a food transporter carries it into the cell.
What is known about harm
Nothing has been published about side effects in a person, because no published report exists of anyone giving KPV to a person by any route, and there is no case series from people who have used it either. Every result on record is in rodents or in cells in a dish. The entry names no safety or toxicology study in any species, so the empty record here means untested rather than clean.
The arithmetic
KPV is sold in 5 mg vials. Mixing errors put people an order of magnitude off using a perfectly good vial, and the arithmetic is simple enough to check yourself.
Vial
Water
Concentration
In 10 units
5 mg
1 mL
5 mg/mL
500 mcg
5 mg
2 mL
2.5 mg/mL
250 mcg
5 mg
3 mL
1.67 mg/mL
167 mcg
10 units is 0.1 mL on a U-100 insulin syringe, whatever is in it. For any other combination, or to see the arithmetic worked out, use the calculator.
Everything on this page is a summary. The citations, the studies and the reasoning live in the full entry.