A COA rarely shows a number on its own. Next to each result, it names the method used to get it. Two show up on almost every peptide COA: high-performance liquid chromatography (HPLC) and mass spectrometry (you’ll see “MS” or “LC-MS”). This guide explains what each one reports, and why the method matters as much as the number beside it. It stays at the level of the record — what the methods show on paper — not how any material is used. If the COA format is new, start with How to Read a Peptide COA.
Why methods appear on a certificate of analysis
A COA is a record of measurement, and a measurement only means something when you know how it was made. Naming the method turns a bare figure into a traceable claim: it tells the reader which instrument produced the result, and therefore what question that result actually answers.
Different methods answer different questions. One method may speak to how much of the sample is the intended material; another may speak to whether the material is what the label says. Because these are separate questions, a complete record usually reports more than one method. When you see HPLC and mass spectrometry listed together, the COA is answering two of the most important questions a documentation reader can ask.
HPLC: what it measures and why it maps to the result figure
High-performance liquid chromatography separates the components of a sample and measures how much of each is present. In practice, the sample is carried through a column that pulls its components apart in time, so that each one arrives and is detected separately. The instrument records these as peaks, and the relative size of the peaks is what gets summarized as a result figure (often called purity).
That is why HPLC maps to the result figure on a COA. It answers “of everything detected in this sample, what proportion is the main component?” — a proportion, expressed as a percentage.
On the published PolarLabs record for BPC-157, lot PL-BPC10-0826-01, tested by Freedom Diagnostics, the published test result is 99.62% (certificate ID POLA2608310062, test date September 2, 2026; net content 11.91 mg). Read structurally, that figure reports how much of the analyzed material is the main component. A result percentage like this is the kind of figure HPLC produces — but note that the record’s on-page summary labels it a “test result” and does not name the method, so treat the specific method (HPLC) as confirmed only where the certificate itself states it.
Mass spectrometry: what it measures and why it maps to identity
Mass spectrometry measures the mass of a sample’s components. Every compound has a characteristic mass, so measuring mass lets an analyst check whether the material present matches the expected material. Rather than asking “how much,” mass spec asks “is this the thing it is supposed to be?”
That is why mass spectrometry maps to identity on a COA. An identity result confirms — or fails to confirm — that the compound in the sample is the one named on the label. On a record, the identity line typically states that the measured mass is consistent with the expected compound; the COA reports this as a confirmation rather than as a percentage.
On any record that reports it, the mass spectrometry result is the identity confirmation. We describe it structurally because identity is reported as a confirmation, not a figure — the value to read is the confirmation statement itself, wherever the COA presents it. The published BPC-157 record does not display an identity line in its on-page summary, so treat identity as confirmed only where a record explicitly reports it.
Reading a method result and its reported value
A method result on a COA has two parts worth reading together:
- The method name — what was measured (HPLC for the result figure, mass spec for identity).
- The reported value — the outcome of that measurement (a percentage for the result figure, a confirmation for identity).
| Method | Question it answers | Form of the result | On the BPC-157 record |
|---|---|---|---|
| HPLC | How much of the sample is the main component? | A percentage | Published test result: 99.62% (method not named on the on-page summary) |
| Mass spectrometry | Is the material what the label states? | A confirmation | Not shown on the on-page summary; where a record reports it, read the confirmation statement |
Reading the pair, rather than the number alone, keeps you from misreading one method’s result as if it answered the other’s question. A high result percentage does not, by itself, confirm identity — that is a separate line, produced by a separate method.
What the methods together tell you about a record
Taken together, HPLC and mass spectrometry let a record speak to both questions at once: how much of the intended material is present, and whether that material is what the label states. A record that reports only one leaves the other question open. A record that reports both — a result figure and an identity confirmation — is more complete, because it closes both.
This is why documentation readers look for method names, not just results. The methods are the evidence for the numbers, and a COA that names them is a COA that shows its work.
Where to find the underlying report
The method results you read in a summary come from an underlying laboratory report — the document the testing laboratory issued for that specific lot. On the BPC-157 record, that report is identified by certificate ID POLA2608310062 and tied to lot PL-BPC10-0826-01; it is hosted by the laboratory and opens on the lab’s own website. The summary is a reading aid; the report is the record.
You can reach these records through the Verification Center, which organizes published documentation by product and lot.