“HPLC tested” appears on a lot of peptide listings. This guide explains what HPLC actually measures, how it differs from mass-spectrometry identity testing, and how to read the result so the phrase means something.
What HPLC measures
HPLC (high-performance liquid chromatography) separates the components in a sample and measures how much of each is present. For a peptide, it reports purity — the percentage of the sample that is the target peptide, usually shown as a main peak on a chromatogram with any impurities as smaller peaks.
HPLC purity vs mass-spec identity
| Test | Question it answers | Output |
|---|---|---|
| HPLC | How pure is it? | Purity %, chromatogram |
| Mass spectrometry (MS) | Is it the right molecule? | Measured molecular weight vs expected |
Purity and identity are different questions. A sample can be highly pure but not the molecule you ordered — which is why a complete testing record reports both. See our COA guide for how these appear on a certificate.
How to read an HPLC result
- Main peak % — the headline purity figure (we hold a ≥99% standard).
- The chromatogram — a clean trace with one dominant peak is what you want.
- Who ran it — independent third-party testing carries more weight than in-house numbers.
Why third-party testing matters
In-house results can be accurate, but an independent lab has no incentive to flatter the product. We send every batch to a third-party lab (Janoshik Analytical) and publish a batch-matched COA — so “HPLC tested peptides in Canada” is a claim you can verify, not just a label.
Lab-tested research peptides you can verify
Every batch is independently HPLC + mass-spec tested with a batch-matched COA.
Frequently asked questions
Is a higher HPLC purity always better?
Higher purity is generally preferable, but purity alone doesn’t confirm identity. Look for both an HPLC purity figure and a mass-spec identity result.
What purity standard do you hold?
We hold a ≥99% purity standard, supported by chromatograms, and confirm identity by mass spectrometry.
What does ‘third-party tested’ mean?
Testing performed by an independent lab rather than the seller, reducing conflict of interest. We use an independent analytical lab for every batch.
This guide is general educational information about laboratory testing methods, not medical or legal advice.