What is in a peptide stack: Klow, Glow and Wolverine compared

The short answer. A peptide stack is a single vial containing more than one lyophilised peptide, supplied together rather than as separate vials. Wolverine contains two peptides, Glow contains three, Klow contains four. The exact quantity of each is measured by an independent laboratory for every batch and published, so the composition is a matter of record rather than a description.

For research purposes only. Not for human consumption. 18+. UK only. This article describes the composition and testing of laboratory research materials. It does not describe effects, uses, dosing or administration, and nothing here is a claim about what any compound does.

What a "stack" actually means

The word does a lot of work in this market and is rarely defined. In practice it means one thing: several peptides, lyophilised together, in one vial.

That is a supply format, not a scientific category. There is no property a stack has that its individual components do not. What it changes is practical: one vial instead of several, one reconstitution instead of several, and one certificate covering the combination.

It also changes what testing can tell you, which is the part most suppliers skip over. That is covered further down.

The three stacks, side by side

Figures below are the measured content by mass from the June 2026 batch assay, carried out by Janoshik Analytical. Every number links to the laboratory's own verification page.

Three things are worth reading out of that table.

Klow is Glow plus KPV. The two share the same three peptides in similar quantities, and Klow adds a fourth. If you are comparing them, that is the whole difference.

GHK-Cu dominates both Glow and Klow by mass. At roughly 55 to 58 mg it makes up about two thirds of the vial. The remaining peptides sit in the 11 to 13 mg range. A headline figure of "80 mg" or "70 mg" is not evenly divided between the compounds, and no stack's total should be read as though it were.

Wolverine is the smallest and the simplest. Two peptides, roughly 25 mg in total, in near equal parts.

What the certificate proves for a stack, and what it does not

This is where multi-peptide vials differ from single ones, and it is worth being exact about.

A single peptide vial can be tested two ways at once. Mass spectrometry confirms identity, that the vial contains the compound named on the label. High performance liquid chromatography reports purity, the proportion of the sample that is the target compound rather than impurities. That is where a figure like 99% comes from.

A stack cannot be given a single purity percentage. With four peptides in one vial, chromatography separates four intended compounds, so there is no single "target" to express the rest as a proportion of. The question does not have an answer in that form.

What a blend assay does instead is confirm identity for each peptide present, and measure content by mass for each one. That is what the numbers in the table are.

So for a stack:

• You can verify which peptides are in the vial.
• You can verify how much of each, in milligrams.
• You cannot get a single HPLC purity percentage, and any supplier quoting one for a multi-peptide vial is quoting something that does not exist.

That last point is a useful test when comparing suppliers.

How to check any of this yourself

Nothing above needs to be taken on trust. Each report number in the table links to Janoshik's own verification page, which is the laboratory's record, not ours. Enter the number there and the result comes back from them.

If you want to work through what the fields on a report mean, there is a step by step guide at how to read a Certificate of Analysis, and a walkthrough of checking a report at source at verify a certificate.

Common questions

What is the difference between the Klow Stack and the Glow Stack? Klow contains the same three peptides as Glow, GHK-Cu, TB-500 and BPC-157, plus a fourth, KPV, at 10.95 mg in the June 2026 batch. Total measured content was 88.59 mg for Klow against 83.55 mg for Glow.

What is in the Wolverine Stack? Two peptides. In the June 2026 batch the assay measured BPC-157 at 14.13 mg and TB-500 at 10.99 mg, for a total peptide content of 25.12 mg.

Why is there no purity percentage on a stack? Purity by HPLC is expressed as the proportion of a sample that is one target compound. A vial containing several intended peptides has no single target, so the figure has no meaning. Blend vials are instead tested for the identity of each peptide and the content by mass of each.

Is a stack the same as buying the peptides separately? As supplied, a stack is one vial containing several lyophilised peptides rather than several vials. The compounds are the same compounds. Individual reference pages for each are in the compound library.

How do I know the quantities are accurate? They are measured by an independent laboratory for each batch, and each report can be confirmed on that laboratory's own website using the report number. See verify a certificate.

What water is used to reconstitute a stack? The same as for any lyophilised research material. Bacteriostatic water is used where a vial will be drawn from more than once. There is a reference page at bacteriostatic water.

Where to look next

• Verify a Certificate of Analysis at source
• How to read a Certificate of Analysis
• All published lab reports
• Compound library