GLOW Stack (GHK-Cu + TB-500 + BPC-157) vs TB-500

GLOW Stack (GHK-Cu + TB-500 + BPC-157)

This product is a blend of three research peptides, GHK-Cu, TB-500 and BPC-157, supplied together in a single preparation. GHK-Cu is the copper(II) complex of the tripeptide glycyl-histidyl-lysine, first isolated from human plasma. TB-500 is the synthetic seven-residue fragment Ac-LKKTETQ, copied from the actin-binding region of thymosin β4. BPC-157 is a synthetic 15-residue peptide whose sequence was taken from a protein described in gastric juice. Each has its own literature, mostly in cell culture and animal models, but no published study has tested the three together, and there are no data on their stability or behaviour as a mixture.

TB-500

TB-500 is a synthetic seven-residue peptide, Ac-LKKTETQ, matching residues 17 to 23 of the 43-residue actin-binding protein thymosin β4. The stretch it copies lies in the central actin-binding region of thymosin β4; the N-terminal acetyl cap is a synthetic addition, since that position is internal in the native protein. The name is sometimes applied loosely to full-length thymosin β4, and the two should be kept apart: they differ in length, in mass (about 0.9 kDa against about 5 kDa) and in which parts of the parent protein they contain. Most published research concerns the full-length protein, examined in cell culture and in rodent models of skin, cardiac and corneal injury. Work on the fragment alone is far thinner, and it cannot be assumed to share the properties described for the whole protein.

How GLOW Stack (GHK-Cu + TB-500 + BPC-157) acts

No mechanism has been described for the blend itself, so only the components can be discussed, each on its own evidence. GHK binds copper(II) with high affinity, and the complex has been examined in fibroblast cultures for changes in collagen and glycosaminoglycan synthesis. Thymosin β4 binds monomeric actin and regulates how much is available for filament assembly; TB-500 copies LKKTETQ, the short sequence at the centre of that binding region, and how far the fragment shares the binding is not well established. The mode of action of BPC-157 is unsettled, with rodent and cell studies examining nitric oxide signalling and VEGF receptor pathways. Whether the three interact with one another has not been investigated.

How TB-500 acts

Full-length thymosin β4 binds monomeric G-actin in a one-to-one complex and is a major actin-sequestering protein in many cell types, holding actin in unpolymerised form. Structural studies place the LKKTET motif, shared with the WH2 family of actin-binding domains, at the centre of that contact, flanked by N-terminal and C-terminal segments that also touch actin. A small number of cell studies have reported that the isolated fragment affects endothelial cell migration, but how closely it reproduces the actin binding of the whole protein is not well established. Other activities attributed to thymosin β4 map elsewhere: the N-terminal tetrapeptide Ac-SDKP is released by enzymatic cleavage and has been studied separately.

The records side by side

• Type: GLOW Stack (GHK-Cu + TB-500 + BPC-157), Three-peptide blend; TB-500, Heptapeptide (thymosin β4 fragment)
• Length: GLOW Stack (GHK-Cu + TB-500 + BPC-157), not recorded; TB-500, 7 amino acids
• Molecular weight: GLOW Stack (GHK-Cu + TB-500 + BPC-157), not recorded; TB-500, 889.0 g/mol
• Molecular formula: GLOW Stack (GHK-Cu + TB-500 + BPC-157), not recorded; TB-500, C38H68N10O14

Reading a comparison

A comparison places two records side by side; it does not merge them. Each description above is drawn from that compound's own record, and the two were not necessarily characterised by the same methods, at the same time, or to the same level of detail. Before comparing any attribute, it is worth establishing that both records describe the substance you think they describe — names are not identifiers, and two entries sharing a name can differ in salt form, stereochemistry or the convention used to state a mass. Where a figure carries no method beside it, the comparison is between two reported numbers rather than between two measurements.