KLOW, the four-part peptide: what is known about each part and what is not
· Novatheris
KLOW is not a single peptide. It is a blend of four in one 80 mg vial: GHK-Cu, BPC-157, TB-500 and KPV. Anyone looking up the KLOW peptide tends to find texts that treat the blend as one molecule with results of its own. It has none. Here is what has been published on each part, with its source, and what is missing.
First, and most important: there is not a single study of the KLOW blend in any species. Not in cells, not in animals, not in people. Everything below is about the components on their own.
What the KLOW peptide is
The name comes from combining four compounds that are studied separately in skin, tendon and inflammation research:
- GHK-Cu: a copper tripeptide that circulates in human plasma.
- BPC-157: a 15-amino-acid peptide derived from gastric juice.
- TB-500: a seven-amino-acid fragment of thymosin β4.
- KPV: a tripeptide, Lys-Pro-Val, the last three amino acids of α-MSH, a hormone the body makes.
One fact is not public: how the 80 mg are split among the four. There is also no data on how they behave together in the vial, or on whether one changes the stability of another.
GHK-Cu: the copper part
GHK-Cu was described by Loren Pickart in 1980. His work showed that the tripeptide exists in human plasma, binds copper and iron, and that in culture those complexes stimulated the growth of hepatoma cells (Pickart and Thaler, 1980).
In 1993, in rats with wound chambers placed under the skin, the copper complex increased the buildup of collagen and other connective tissue components (Maquart et al., 1993).
That is in rats. The two human trials that exist with GHK-Cu were topical, applied to the skin, and both came out negative. That topic has its own article.
BPC-157: the most studied part in animals
The most cited paper is from 2003. In rats with a transected Achilles tendon, the treated group showed faster tendon closure, and in culture the peptide stimulated the growth of tendon cells (Staresinic et al., 2003).
On how long it lasts in the body there is one study, and it is in animals. In rats and dogs, the half-life was under 30 minutes (He et al., 2022). In humans there is none.
A 2026 review puts it plainly: no validated formulation, no validated regimen and no completed phase II trial (Mateescu et al., 2026).
TB-500: a piece, not the whole protein
TB-500 is a seven-amino-acid peptide with one modified end: Ac-LKKTETQ. It matches a part of thymosin β4, the region that binds actin, a protein that gives the cell its shape.
Its chemical identity was established in 2012, when an analytical laboratory synthesized and characterized the fragment found in the product already in circulation (Esposito et al., 2012).
Full thymosin β4 has 43 amino acids. TB-500 has seven. The human studies sometimes cited in support were run with the full protein, which is a different molecule. For the TB-500 fragment, there is no published human study.
KPV: the least known part
KPV is the smallest piece: three amino acids, lysine, proline and valine. They are the tail end of α-MSH, a hormone the body makes that takes part in the response to inflammation.
The reference study is from 2008, in mice with colitis, an inflammation of the gut. The authors saw that KPV enters gut cells through a transporter called PepT1, and that in those mice inflammation went down (Dalmasso et al., 2008).
It is a mouse study, with KPV alone. It says nothing about what it does inside a blend.
The only data on two parts together
Of the four pieces, only two have been put together in a published study: BPC-157 and TB-500.
In 32 rats with a repaired Achilles tendon, groups given BPC-157, TB-500 or both were compared. The TB-500 arm reached statistical significance in how much force the tendon held before breaking. The BPC-157 arm did not. And combining the two gave no additional benefit over using either one alone (Biçer et al., 2026).
That result matters for KLOW. The idea that adding peptides adds up their effects has no support, and the only study that tested it with two of these four pieces did not see it.
What is still unknown about the blend
For the notebook:
- There is no study of KLOW as a blend, in any species.
- How the 80 mg are split among the four is not public.
- There is no interaction or stability data for the four together.
- For TB-500, there is no human study at all.
- For BPC-157, there are no controlled human trials.
- KPV was studied in mice, on its own.
A 2026 review for sports medicine physicians says it about these compounds in general: indications, amounts, frequency and duration are unknown (Mayfield et al., 2026).
How it is stored
KLOW comes lyophilized, which means dry: a powder whose water was removed with cold and vacuum. Because of the copper in GHK-Cu, that powder usually looks blue.
It is kept at -20 °C, closed and away from bright light. Let the vial reach room temperature before opening it, so moisture does not get in. Once reconstituted, it goes to 2 to 8 °C and for a short time.
Where to find it
Every batch of KLOW is sent to an outside laboratory. The report published today is from Freedom Diagnostics, for the 80 mg vial, and you can see it in full exactly as the laboratory issues it. The standard we ask for is +99.5% purity. Delivery takes 2 hours in the GAM and 24 hours in the rest of Costa Rica.
If you are putting together a research protocol, the KLOW page has the data on all four components, and the KLOW lab analysis has the batch report. If you prefer to work with the pieces separately, there is also the BPC-157 / TB-500 page. For research use only.