Judging blends: why a mixture follows different rules
A blend is convenient: fewer vials, fewer steps. But everything you can check about a single substance works differently with a mixture, or not at all.
99 percent of what?
A purity figure from an HPLC run is one substance’s peak divided by all peaks together. In a mixture of three peptides there are three main peaks. A single figure of 99 percent can then mean two things, and neither is what you are looking for.
It can be the purity of one of the three, measured before they were mixed. Or it can be the sum of the three peaks against the clutter around them. The latter does say something about contamination, but nothing about the ratio between the three.
What to ask for instead
- A measurement per component, each with its own percentage.
- The established ratio between components, not only the intended ratio.
- An MS confirmation per component, so each molecule really is what it says.
- The lot number of the blend, not of the separate raw materials.
Three substances in a vial have three different rates of decay. The one with the shortest shelf life decides how long the whole stays usable. In a KLOW mixture with four components you therefore depend on the most fragile one, even if the other three are still fine.
Why blends exist anyway
There are good reasons. Substances working along different routes reinforce each other in research: a GHRH peptide next to a ghrelin peptide, or BPC-157 next to TB-500. Putting them in one vial saves handling steps and with them chances to go wrong.
The objection is not the mixing itself, but that you give up control. You can no longer adjust the ratio and you can no longer tell which component caused an effect.
For a study design
If you want to know what a substance does, a blend is unsuitable. Any result can come from any component, or from the combination. That is not a small reservation; it makes the outcome uninterpretable.
If you want to know what a combination does, a blend is exactly right, as long as you know the ratio. Without that ratio you do not know what you tested and you cannot repeat it.
The well known mixtures
| Name | Components |
|---|---|
| Wolverine | BPC-157 + TB-500 |
| GLOW | BPC-157 + TB-500 + GHK-Cu |
| KLOW | BPC-157 + TB-500 + GHK-Cu + KPV |
| CagriSema | Cagrilintide + semaglutide |
| CJC + Ipa | CJC-1295 without DAC + ipamorelin |
With the mixtures containing GHK-Cu there is one extra handle: the blue colour. It tells you whether the copper part is intact. About the other components the colour says nothing.
This site is made by the team behind Apex Bio Research, a Dutch supplier of research peptides with a certificate of analysis per batch.
Visit the shopThis site explains what the scientific literature says about peptides. It is not medical advice and not a set of instructions. The substances discussed here are research compounds: they are not approved for use in humans or animals. If you have a health question, see a doctor.
Read next
Reading a certificate of analysis
What belongs on a CoA, what a purity figure does and does not mean, and how to tell whether a certificate belongs to your vial.
Repair peptides: BPC-157 and TB-500
Two peptides often named in one breath but working along very different routes. Where they come from and what the literature says.