Reference
What a peptide blend is
Several peptides freeze-dried together in one vial. Nothing new has been made — but every number on an analytical report now means something different.
A blend is a packaging decision. Two or more peptides, each made separately and purified separately, are combined in solution and lyophilised together so that one vial holds all of them. The molecules do not react with one another and nothing is created. What changes is what a single figure printed on a document can possibly be describing.
A blend is not a compound
Worth saying flatly, because the naming encourages the opposite reading. GLOW and KLOW look like the names of substances. They are not. They are names for particular combinations, and they have:
- no sequence of their own — they have several;
- no molecular weight of their own — a molecular weight describes one molecule, and there is no one molecule here;
- no CAS number, no international nonproprietary name, no chemical identity at all.
In this range the blends are GLOW (GHK-Cu, BPC-157, TB-500), KLOW (the same three plus KPV), and a BPC-157 and TB-500 blend. The names are acronyms of their constituents, which is the most useful thing about them.
What it does to a purity figure
This is the part worth understanding before reading any document about a blend.
HPLC purity is calculated by area normalisation: the detector traces everything that comes off the column, the areas under the peaks are added up, and the target peak's share of the total is the purity figure. That calculation assumes there is one target peak.
A three-component blend produces three large peaks. Asking for "the purity" of that trace is asking a question the method is not built to answer, and there are several things a supplier might do with it:
- Report each constituent separately — three peptides, three purity figures, plus the ratio between them. This is the informative version.
- Report the combined area of the three target peaks as a single percentage. That number is not meaningless, but it says nothing about whether the ratio is right.
- Report a single figure with no explanation of which of the above it is. This is the common version and it cannot be interpreted.
The practical consequence: a purity figure quoted for a blend without saying what it is a percentage of is not a figure you can compare with anything.
The ratio is a formulation claim, not a chemical one
A blend is defined by its proportions as much as its constituents. Change the ratio and it is a different product with the same name, and no analysis of the individual peptides will tell you whether the ratio was hit — that is a question about weighing and mixing, not about chemistry.
It also means the total on the label is a sum. A vial marked 70mg holds 70mg across three peptides, not 70mg of each. The same fill weight and net peptide content questions apply on top of that, to each constituent separately.
Why blends exist
One vial instead of three is cheaper to fill, cheaper to ship and cheaper to document as a single batch. That is the honest reason and it is a perfectly good one. It is not evidence that the combination does anything, and this site makes no claim that it does — blends are listed in their own category on the families page precisely so they are not mistaken for a class of molecule.
What to look for on a blend's paperwork
- Is each constituent identified individually, by mass?
- Is a purity figure given per constituent, or one figure for the vial?
- If one figure, is it stated what it is a percentage of?
- Is the ratio stated, and is there anything supporting it?
- Is net peptide content given per constituent, or at all?
Most blend documentation in this trade answers one or two of those. That is worth knowing before comparing two blends on a single printed number.
The families of research peptides · What an HPLC purity figure measures · The range
Buy in New Zealand
Prices, sizes and stock: GLOW in New Zealand · KLOW in New Zealand.
