GHK-Cu blends explained: GLOW and KLOW compositions
GLOW and KLOW are names for multi-component research blends built around the copper tripeptide GHK-Cu. They are not new molecules: each is a defined mixture of well-characterized peptides lyophilized together in one vial. This guide lists what is in each blend and explains how a lot containing several peptides is checked.
Composition
| Component | GLOW | KLOW |
|---|---|---|
| GHK-Cu | 50 mg | 50 mg |
| BPC-157 | 10 mg | 10 mg |
| TB-500 | 10 mg | 10 mg |
| KPV | – | 10 mg |
| Total peptide | 70 mg | 80 mg |
GHK-Cu is the major component by weight in both blends. Because the components have very different molecular weights, the ratio by mass is not the ratio by number of molecules: 50 mg of GHK-Cu is roughly 124 µmol, while 10 mg of BPC-157 is about 7 µmol. Keep this in mind when comparing a blend with single-compound studies, which usually report molar concentrations.
The components
| Component | Sequence | Average MW (g/mol) | Notes |
|---|---|---|---|
| GHK-Cu | Gly-His-Lys, copper(II) complex | ≈ 401.9 (free GHK 340.4) | Blue-violet color from bound copper |
| BPC-157 | GEPPPGKPADDAGLV | ≈ 1419.6 | 15 residues |
| TB-500 | Ac-LKKTETQ | ≈ 889.0 | N-acetylated fragment of thymosin beta-4 |
| KPV | Lys-Pro-Val | ≈ 342.4 | C-terminal tripeptide of α-MSH |
Each component has its own research history: GHK-Cu in fibroblast and wound-model studies, BPC-157 and TB-500 in rodent tissue-injury models, and KPV in intestinal and skin-cell inflammation models. Our GHK-Cu overview, BPC-157 vs TB-500 and KPV overview cover those literatures in detail.
No published literature on the blends themselves
There are no peer-reviewed studies of GLOW or KLOW as mixtures. The names describe a composition, not a studied formulation, and any published data refers to the individual components studied on their own. Researchers using a blend should regard it as four (or three) separately characterized compounds combined in known amounts.
How a multi-component lot is verified
A certificate of analysis for a blend has to show that every component is present and identifiable, not just that the vial holds peptide.
- HPLC with separate peaks. The components differ in size and hydrophobicity, so reversed-phase HPLC resolves them as distinct peaks at different retention times. The chromatogram should show one main peak per component, with relative areas broadly consistent with the stated ratio. A single overall purity figure is less informative here than the per-peak picture.
- Mass spectrometry per component. Each peak, or the combined spectrum, should show ions matching each expected mass: about 1419.6 for BPC-157, 889.0 for TB-500, 342.4 for KPV, and GHK or its copper complex for GHK-Cu, depending on the method.
- The copper complex. Under acidic mobile phases, GHK-Cu can partly dissociate, so the report may show free GHK (340.4) rather than the complex. Both are consistent with GHK-Cu.
- The TB-500 name. Some sources use “TB-500” for full-length thymosin beta-4 (about 4963 g/mol). The mass panel confirms which form is present.
For background on both panels, see HPLC purity: what the percentage means and reading a mass spectrum on a peptide COA.
Storage
A blend is only as stable as its least stable component. Keep vials sealed, dry, cold and away from light, as for any lyophilized peptide.
All LA Peptides products are supplied for laboratory research use only and are not for human or veterinary use.
More guides
- BPC-157 vs TB-500: two research peptides compared
- Reading a mass spectrum on a peptide COA: m/z, charge states and adducts
- CJC-1295 with and without DAC: what the names mean
- Short peptide bioregulators: an overview for researchers
- Why a peptide's molecular weight can differ: salts, caps and oxidation
- Thymosin alpha-1: structure, history and research
- Epitalon (AEDG): what the research covers
- KPV: the α-MSH tripeptide explained
- MOTS-c: the mitochondrial-derived peptide explained
- Adamax and Semax: what is known about this analog
- Selank: the tuftsin-derived heptapeptide explained
- SNAP-8 vs Argireline: two SNAP-25 mimic peptides compared
- AHK-Cu vs GHK-Cu: comparing two copper tripeptides
- GHK-Cu: structure, history and published research
- HPLC purity: what the percentage on a COA means
- Mass spectrometry: how a peptide's identity is confirmed
- How to verify a lot with the QR code on the vial
- Lyophilized peptides: what they are and how labs store them
- How to choose a research compound supplier: 7 points
- How to read a certificate of analysis (COA)
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All LA Peptides products are sold for laboratory research only. Not for human or veterinary use.
View GLOW and its per-lot certificate of analysis
For laboratory research use only. Not for human or veterinary use. This guide summarizes published scientific literature for context. It is not medical advice and does not describe any product as suitable for human use.