What the GLOW blend is
GLOW, often listed as the GLOW peptide blend, is a co-lyophilised preparation of three peptides that are frequently ordered together: GHK-Cu, the copper(II) complex of the tripeptide Gly-His-Lys first isolated from human plasma; BPC-157, the 15-residue fragment of a human gastric protein; and TB-500, the N-acetylated seven-residue fragment of thymosin beta-4 that carries its actin-binding motif. The three are dissolved together in the stated amounts, 50 mg, 10 mg and 10 mg, freeze-dried together in a single vial. The resulting blue powder is a physical mixture at a fixed ratio by mass, not a conjugate; the peptides are not covalently linked and behave independently once in solution.
GHK-Cu dominates the vial by mass and by moles, since at roughly 404 g/mol for the complex 50 mg is about 124 micromoles, against about 7 micromoles of BPC-157 and 11 micromoles of TB-500. The blend is listed in our blends class.
What you receive
Each vial contains the three peptides as a blue lyophilised powder, sealed with a flip-off cap over a crimped stopper, in the net quantities stated on the label: 50 mg of GHK-Cu, 10 mg of BPC-157 and 10 mg of TB-500, 70 mg in total. There is no carrier, mannitol or other excipient unless the batch certificate says otherwise. The batch number is printed on the label and matches the certificate in our register. The limitation of a blend is its fixed ratio; a design that needs any component varied independently should use the single-compound vials.
Reading the certificate for a GLOW batch
A three-component certificate has more to check than a single-compound one. Identity by LC-MS is confirmed for each component in turn: the laboratory looks for about 340 Da for the GHK tripeptide, since the copper is normally stripped under the acidic conditions of electrospray ionisation and the free peptide is what appears, about 1,419 Da for BPC-157 and about 889 Da for TB-500. A good certificate notes the copper dissociation and, where measured, reports copper content separately so that the complex can be confirmed. Purity by reversed-phase HPLC shows three main peaks, and the reported purity is their combined area against all peaks; above 98% is expected for a well-made lot. Net content is reported for the vial as a whole and, where quantified against standards, per component.
The impurities expected are those of the individual peptides: diketopiperazine from GHK, deletion sequences and aspartimide-related product from BPC-157, and deletion sequences from TB-500. Our guide to reading a certificate of analysis includes a blend example, and the copper peptides compared guide discusses the copper-specific points.
Storage and handling
Sealed vials should be kept refrigerated at 2 to 8 °C and protected from light; −20 °C is preferable for storage beyond a few months. GHK-Cu is noticeably hygroscopic and will clump and darken if it absorbs moisture, so allow the vial to reach room temperature before opening and reseal promptly. The powder dissolves readily in water or bacteriostatic water to give a blue solution containing all three peptides. Chelating agents such as EDTA will strip the copper from GHK, so buffers containing them should be avoided, and solutions should be aliquoted and frozen for anything beyond short-term refrigerated use. The storage and stability guide covers solvents, concentrations and freeze-thaw behaviour.