What Is GLOW?
GLOW is the catalog name for a research blend of three peptides: GHK-Cu, BPC-157 and TB-500. Each has its own literature in cell and animal models, and each is studied through a different pathway. It is the same three-compound base as the KLOW blend, without KLOW's fourth peptide, KPV.
At Prime Peptide Solutions, GLOW is listed as one lyophilized vial with all three peptides pre-mixed, 70 mg total. The 70 mg figure is the total for the whole vial, not the amount of each peptide.
This article is a scientific overview for laboratory researchers. The research-grade GLOW blend listed by Prime Peptide Solutions is sold strictly for in-vitro laboratory research. It is not approved for human use and is not for human or animal consumption.
The Three Components at a Glance
GHK-Cu: the copper-binding tripeptide
GHK is glycyl-L-histidyl-L-lysine (Gly-His-Lys). PubChem lists the free peptide (CID 73587) with the molecular formula C14H24N6O4 and a molecular weight of 340.38 g/mol, and indexes the copper complex under CID 71587328 with the formula C14H23CuN6O4+ and a molecular weight of 402.92 g/mol. A 2012 review states that GHK was discovered in 1973 as an activity in human albumin and that it has high affinity for copper ions, readily forming the GHK-Cu complex.
Crystallographic and spectroscopic work describes the complex as dimeric in the solid state but monomeric in solution, with the copper held by three nitrogen ligands: the terminal amine, an amidyl nitrogen and the histidine imidazole nitrogen. A 2015 review reports that GHK modulates the synthesis and breakdown of collagen and glycosaminoglycans and the activity of metalloproteinases and their inhibitors, and a 2018 review lists suppression of NF-kB among the actions it attributes to GHK. The GHK-Cu research overview covers the molecule in more depth.
BPC-157: VEGFR2 and nitric-oxide signaling
BPC-157 is a 15-residue linear peptide with the sequence Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val (H-GEPPPGKPADDAGLV-OH). PubChem (CID 9941957) lists the molecular formula C62H98N16O22 and a molecular weight of 1419.5 g/mol. The sequence contains no histidine or cysteine.
In cultured human vascular endothelial cells, BPC-157 increased VEGFR2 mRNA and protein without changing VEGF-A, promoted VEGFR2 internalization and time-dependently activated the VEGFR2-Akt-eNOS pathway. The endocytosis inhibitor dynasore blocked both. The same study reported more endothelial tube formation in vitro. A later study in isolated rat aorta found endothelium-dependent, nitric-oxide-mediated vasodilation and proposed a Src-caveolin-1-eNOS pathway. In cultured rat fibroblasts, BPC-157 increased migration along with FAK and paxillin phosphorylation. See the BPC-157 research overview.
TB-500: the actin-binding motif of thymosin beta-4
Thymosin beta-4 is a 43-residue protein of about 5 kDa that binds and sequesters actin monomers (G-actin) and so inhibits actin polymerization; work on human platelets showed a 1:1 complex with actin monomers. In the literature, TB-500 is not the full protein: it is commonly described as N-acetyl-LKKTETQ, a synthetic, N-terminally acetylated version of the LKKTETQ segment (residues 17-23 in the mature 43-residue numbering), described as the site responsible for actin binding and cell migration. PubChem (CID 62707662) lists this peptide with the formula C38H68N10O14 and a molecular weight of 889.0 g/mol.
In human umbilical vein endothelial cell migration assays and chick aortic-arch sprouting assays, thymosin beta-4 and a peptide carrying its seven-amino-acid actin-binding motif showed near-identical activity at about 50 nM, while peptides lacking any part of the motif were inactive.
How the Three Literatures Relate
We found no primary study of this three-peptide combination. The papers that mention several of these peptides are narrative reviews that cover each one individually. The grouping brings three separately studied pathways into one research material; it is not evidence of any combined effect. Side by side, the three literatures cover distinct areas:
- Copper and extracellular-matrix signaling (GHK-Cu): a high-affinity Cu(II) complex linked in reviews to collagen and glycosaminoglycan turnover.
- Endothelial receptor signaling (BPC-157): VEGFR2-Akt-eNOS and nitric-oxide signaling.
- Cytoskeletal dynamics (TB-500): the actin-binding motif of thymosin beta-4 (a G-actin-sequestering protein) and cell migration.
The threads meet at the level of assays: BPC-157 and the thymosin beta-4 motif have both been examined in endothelial cell assays. That overlap shows where the literatures touch, not that the peptides act together.
GLOW vs KLOW
The two blends differ by one compound. GLOW holds GHK-Cu, BPC-157 and TB-500; KLOW holds the same three plus KPV (Lys-Pro-Val, the C-terminal tripeptide of alpha-MSH), whose literature centers on NF-kB and MAP kinase signaling in epithelial and T-cell lines. A design that needs KPV in the same solution as the other three uses KLOW; one that does not uses GLOW. The KLOW vs GLOW comparison sets the two side by side, component by component.
One Pre-Mixed Vial: What a Shared Solution Means
Because GLOW is a single vial, all three peptides share one lyophilized cake and, after reconstitution, one solution: one pH, one diluent volume and one storage history. The GHK-Cu copper complex is therefore present in the same solution as BPC-157 and TB-500. Work that needs independent control of one component uses single-compound vials, which the catalog also lists: GHK-Cu in 50mg and 100mg sizes, and BPC-157 and TB-500 in 10mg vials. BPC-157 and TB-500 are also stocked as a two-peptide pre-mixed vial, Wolverine (BPC-157 + TB-500), which is GLOW without GHK-Cu.
Copper coordination in solution
Structural work on GHK-Cu gives general chemistry relevant to a shared solution. In the solid state, the fourth equatorial position on the copper is filled by a labile carboxylate oxygen, and the authors probed that position by forming ternary complexes of GHK-Cu with glycine or histidine. Copper exchange with GHK-Cu is fast, and the complex is inert under moderate redox potentials, although it can be reduced to Cu(I) at around -0.62 V (versus AgCl/Ag), with release of the copper ion. Solution studies also report that GHK forms copper complexes of different stoichiometries, and suggest that the lysine side-chain amine joins copper binding only at alkaline pH, since it is protonated at physiological pH. The pH of a shared solution therefore bears on which copper species are present.
Metal ions and peptide chemistry
A 1990 review of metal-catalyzed protein oxidation describes how, in the presence of oxygen, Cu(II) or Fe(III) and a suitable electron donor, such systems modify one or a few amino acid residues at metal-binding sites, with relatively little peptide-bond cleavage. This is general protein chemistry, not tested on these peptides or on GLOW, and not evidence that the blend changes in the vial.
Handling and Reconstituting the GLOW Vial
Reconstitute as one vial
GLOW is reconstituted as a single vial with bacteriostatic water (0.9% benzyl alcohol in sterile water), which is sold separately in 3 mL and 10 mL vials. The figure to calculate is the total concentration: 70 mg divided by the volume of diluent added. For example, 70 mg in 2 mL gives 35 mg/mL of total peptide, and 70 mg in 5 mL gives 14 mg/mL.
That is the concentration of the whole blend. Do not assume the three components are present in equal amounts; a per-component concentration needs that component's own mass for the batch. The single-compound calculator presets model vials holding only one compound.
Labeling and storage
Label the reconstituted vial with the date, the diluent volume and the total concentration, and record the batch number. Store sealed vials at 2-8 °C refrigerated, or -20 °C for long-term storage. After reconstitution, keep the solution refrigerated and protected from light, swirl rather than shake it, and avoid repeated freezing and thawing. See the guide to reconstituted peptide stability.
Frequently Asked Research Questions
What is GLOW?
GLOW is a research blend of three peptides, GHK-Cu, BPC-157 and TB-500, listed here as one pre-mixed lyophilized vial, 70 mg total.
What is the difference between GLOW and KLOW?
One compound. Both contain GHK-Cu, BPC-157 and TB-500; KLOW adds KPV.
Is GLOW one vial or three?
One. All three peptides are pre-mixed in a single lyophilized vial, so they share one solution after reconstitution.
Is 70 mg the amount of each peptide?
No. 70 mg is the total for all three peptides together, not a per-component amount.
Is TB-500 the same as thymosin beta-4?
Not as the term is used in the literature. Thymosin beta-4 is a 43-residue protein of about 5 kDa; TB-500 is commonly described in the literature as its acetylated actin-binding segment, N-acetyl-LKKTETQ (889.0 g/mol).
Is GLOW for human use?
No. The research-grade GLOW blend listed by Prime Peptide Solutions is not approved for human use and is not for human or animal consumption. It is supplied only as a reference material for in-vitro laboratory research.
Conclusion
GLOW combines three peptides with separate literatures: GHK-Cu (copper and extracellular-matrix signaling), BPC-157 (VEGFR2-eNOS signaling) and TB-500 (the actin-binding segment of thymosin beta-4). We found no published study of the three together. As one pre-mixed 70 mg vial, the blend shares a single solution, so laboratories work from the total concentration and keep GHK-Cu's copper chemistry in mind when choosing buffers.
Disclaimer: This article is provided for educational and research purposes only. It summarizes publicly available scientific literature and does not constitute medical advice. GLOW and all peptide compounds sold by Prime Peptide Solutions are intended strictly for laboratory research, are not approved for human use, and are not for human or animal consumption. Researchers are responsible for compliance with all applicable regulations in their jurisdiction.
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References & Further Reading
- PubMed: GHK-Cu copper complex structure and chemistry
- PubMed: BPC-157 and VEGFR2-eNOS signaling
- PubMed: Thymosin beta-4 and G-actin sequestration
- PubMed: Metal-catalyzed oxidation of proteins
Research-Grade GLOW
In our catalog, the blend is listed as GLOW, one lyophilized vial with all three peptides pre-mixed, 70 mg total. Batch lab reports are listed by product and batch on our COAs page as they become available.
Sold strictly for in-vitro laboratory research. Not for human or animal consumption.