Per vial composition is labelled component by component rather than as a proprietary total. The GLOW vial is labelled as GHK-Cu 50 mg, BPC-157 10 mg and TB-500 10 mg. The KLOW vial is labelled as KPV 10 mg, GHK-Cu 50 mg, BPC-157 10 mg and TB-500 10 mg. Component level labelling matters for a blend, because a combined mass figure makes it impossible to reason about the contribution of any single constituent, and because each constituent carries its own identity and purity to certify.
The shared constituents are well characterised individually. GHK-Cu, CAS 49557-75-7, is the tripeptide glycyl-L-histidyl-L-lysine complexed with copper two, formula C14H24CuN6O4, average mass 403.92, and it is the only component carrying a metal. BPC-157, CAS 137525-51-0, is C62H98N16O22 at 1419.53 with the fifteen residue sequence H-Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val-OH. TB-500, CAS 885340-08-9, is C38H68N10O14 at 889.02, the acetylated heptapeptide Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln-OH taken from the actin binding site of thymosin beta-4. No molecular values are recorded for either blend itself, since a mixture has no single formula, so the vials are described by their constituents.
KPV is the differentiator. It is catalogued under CAS 67727-97-3 as Lys-Pro-Val, formula C16H30N4O4, average mass 342.44, the three residue carboxy terminal fragment of alpha melanocyte stimulating hormone, also written as alpha-MSH(11-13). At 342.44 against 889.02 for TB-500, it is the smallest peptide in either vial, and the whole set spans a narrow range from 342 to 1419 daltons. Published work studies it in inflammation models, where the reported line of investigation concerns nuclear factor kappa B signaling and inflammatory cytokine expression in cell culture and in rodent colitis models. Unlike the parent hormone it carries no melanocortin receptor message sequence, so the pigment related activity of alpha-MSH is not part of its described profile.
The two vials therefore differ in what an experiment can address with them. The three component mixture combines a copper carrier tripeptide with two peptides studied in tissue repair models. The four component mixture adds an inflammation oriented fragment to the same set. Researchers who want to separate a repair readout from an inflammatory readout in the same preparation use the four component vial and compare it against the three component vial, which functions as the matched control. Running only one of the two leaves the KPV contribution unresolvable.
Handling is dictated by the most fragile constituent, and in both vials that is the copper complex. GHK-Cu gives reconstituted material a distinct blue tint, which is expected and is not a defect. Copper two is redox active, so solutions are kept away from reducing agents and strong chelators, protected from light, and not warmed. None of the peptide constituents carries a methionine or a cysteine, so oxidation of the peptides themselves is not the concern here. Both blends are lyophilized powders held at minus 20 degrees Celsius protected from light and moisture, reconstituted by swirling gently down the vial wall rather than shaking, refrigerated at 2 to 8 degrees Celsius once in solution, and aliquoted so that repeated freeze thaw is avoided. Components cannot be separated once dissolved.
What is unsettled applies to both vials equally. Mixture studies cannot attribute an observed effect to any one constituent without single component arms run in parallel, and no published work has characterised these particular component ratios as a defined system. Interaction between the copper complex and the peptides in shared solution is also not well described in the literature.