What is in a peptide blend: GLOW, KLOW and two-component kits

A blend is one vial containing more than one peptide, freeze-dried together. The names that circulate online, GLOW and KLOW and various two-part combinations, describe compositions rather than trademarks, and different suppliers use them for slightly different mixtures. This page states exactly what is in the blended kits listed here, so the names can be checked against the contents instead of taken on trust.

GLOW

The GLOW blend contains three peptides per vial:

| Component | Amount per vial | Chemistry | |---|---|---| | BPC-157 | 10 mg | 15-residue peptide, GEPPPGKPADDAGLV, MW 1419.5 | | GHK-Cu | 50 mg | Gly-His-Lys tripeptide complexed with copper(II), MW 403.9 | | TB-500 | 10 mg | Acetylated heptapeptide Ac-LKKTETQ, MW 889.0 |

The copper complex is present at five times the amount of either peptide, which is why a GLOW cake is visibly blue rather than white. That colour comes from the copper(II) ion in GHK-Cu and is expected.

KLOW

The KLOW blend is GLOW plus a fourth component:

| Component | Amount per vial | |---|---| | BPC-157 | 10 mg | | GHK-Cu | 50 mg | | TB-500 | 10 mg | | KPV | 10 mg |

KPV is the tripeptide lysine-proline-valine, CAS 67727-97-3, molecular weight 342.4 g/mol: the last three residues of α-melanocyte-stimulating hormone. It is also listed on its own in the immune family.

Two-component kits

Three simpler blends are listed:

• BPC-157 + TB-500, supplied at 5 mg of each or 10 mg of each per vial.
• CJC-1295 (no DAC) + Ipamorelin, 5 mg of each per vial. The CJC-1295 here is the version without the drug affinity complex linker, a 29-residue GHRH analogue, paired with a five-residue synthetic peptide.
• Selank + Semax, two heptapeptides that share a C-terminal Pro-Gly-Pro tail.

What a blend's specification covers, and what it does not

Each component of a blend has its own product page carrying sequence, CAS number, molecular formula and molecular weight. The blend page carries the composition and the amounts, because those are the properties of the kit as supplied.

Two consequences follow, and both are easy to gloss over. A purity figure for a blended vial is a different measurement from a purity figure for a single peptide: the chromatogram has several main peaks rather than one, and the number reported depends on how the laboratory integrated them. And the amounts stated are what the manufacturer weighs into the vial before drying, not an assay of the finished cake, unless the batch report says otherwise.

Where a batch report is published for a blend it appears in the report library with the other certificates, and the note on reading a report applies to it in the same way.

Why blends exist at all

The practical reason is packaging. Freeze-drying three peptides into one vial means one seal, one label and one batch record instead of three. The names stuck because they are shorter than the compositions, which is also how "wolverine blend" and similar phrases entered circulation for BPC-157 and TB-500 combinations.

The names carry no specification of their own. Two vials labelled GLOW from two suppliers can hold different amounts, and only the composition printed on the product page and the batch report tells you what a particular kit contains.