KLOW peptide is not a single peptide: it is a co-formulated research blend of four synthetic peptides, BPC-157 (10 mg), TB-500 (10 mg), GHK-Cu (50 mg) and KPV (10 mg), supplied as one 80 mg lyophilized vial for in vitro research. This guide takes the blend apart component by component, giving the sequence, CAS number, formula and molecular weight of each, and shows why the molar composition differs so sharply from the mass composition.
What does "KLOW peptide" refer to?
"KLOW" is a catalog name for a four-component blend, and the K marks the addition of the tripeptide KPV to the three-component GLOW composition. Queries for "KLOW peptide", "KLOW blend" and "KLOW blend peptide" all point to the same product, KLOW. There is no molecule called KLOW; in a methods section the material is described by its four components and their identifiers.
| Component | Listed mass per vial | Residues | CAS number | Formula | MW (g/mol) |
|---|---|---|---|---|---|
| BPC-157 | 10 mg | 15 | 137525-51-0 | C62H98N16O22 | 1419.5 |
| TB-500 | 10 mg | 43 | 77591-33-4 | C212H350N56O78S | 4963 |
| GHK-Cu | 50 mg | 3 (copper complex) | 89030-95-5 | C14H23CuN6O4 | 402.92 |
| KPV | 10 mg | 3 | 67727-97-3 | C16H30N4O4 | 342.43 |
Component 1: BPC-157
A 15-residue linear peptide, Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val, C62H98N16O22, 1419.5 g/mol. The sequence corresponds to a fragment of a gastric-juice protein and the peptide is stable in acidic solution. Supplied on its own as BPC-157; chemistry in the BPC-157 and TB-500 primer.
Component 2: TB-500
Synthetic thymosin beta-4: 43 residues, N-terminally acetylated, C212H350N56O78S, about 4963 g/mol, largely unstructured in solution and carrying the actin-binding motif LKKTET. Its molecular weight is the largest in the blend by a wide margin, so at 10 mg it contributes the fewest molecules. Supplied on its own as TB-500.
Component 3: GHK-Cu
The tripeptide Gly-His-Lys complexed with copper(II), C14H23CuN6O4, 402.92 g/mol. At 50 mg it is the largest component by mass and, as the second-lightest molecule, the largest by molarity too; the copper gives the vial its blue colour. See GHK-Cu copper coordination chemistry and GHK vs GHK-Cu.
Component 4: KPV
The tripeptide Lys-Pro-Val, C16H30N4O4, 342.43 g/mol, CAS 67727-97-3. It is the C-terminal fragment, residues 11 to 13, of alpha-melanocyte-stimulating hormone, and it is the lightest molecule in the vial. KPV is studied in cultured-cell models of cytokine signaling, particularly NF-kB-dependent readouts, which is the axis it adds to the blend. It is supplied on its own as KPV, and its profile is KPV: a tripeptide in inflammation research.
What is the molar composition?
By mass the blend is 1 : 1 : 5 : 1. By molarity, after reconstitution in 1 mL, it is about 7.0 mM BPC-157, 2.0 mM TB-500, 124 mM GHK-Cu and 29 mM KPV, a ratio near 3.5 : 1 : 62 : 14.5. The two tripeptides account for more than 90% of the molecules in the vial. Any design that wants the four peptides at matched molarity has to add single components; the blend's ratio is fixed. The full numbers at 1, 2 and 4 mL are in the KLOW 80 mg handling and concentration guide, and the conventions in multi-peptide research blend terminology.
How do you confirm all four peptides are present?
From the COA: four HPLC purities and four mass-spectrometry identities, with observed masses near 1419, 4963, 403 and 342 g/mol. The blue colour confirms copper only. The checklist is in verifying a multi-component blend COA.
Related research guides
- KLOW peptide blend: components and in-vitro research profile
- GLOW vs KLOW: what KPV adds to the blend
- KLOW 80 mg: copper-complex blue powder handling and stability
- What is GLOW peptide? Components, ratios and CAS numbers
- KPV: a tripeptide in inflammation research
Research-use note
All materials discussed are supplied for in vitro laboratory research use only, and are not for human or animal use.
