A certificate of analysis, or COA, is a laboratory’s record of what it found in a sample. For a research peptide it normally states the compound submitted, the compound identified, the purity as a percentage, the method used to measure it and the date of the test. It tells you what is in a vial. It does not tell you that a product is safe, approved or lawful to use.
Key facts
- A COA reports what a laboratory measured, not what a seller claims.
- Purity and identity are two different tests. HPLC measures purity. Mass spectrometry confirms identity. A certificate showing only one of them answers only half the question.
- A certificate is only as good as its traceability: it should name the laboratory, carry a test or report number, and match the batch it is supposed to describe.
- “COA available on request” is not the same as a published certificate. A certificate you can read before ordering is a stronger signal than one you have to ask for.
- In Australia, research peptides are not approved therapeutic goods. A certificate says nothing about legal status, safety or approval.
What a certificate of analysis actually shows
A typical peptide COA has five parts. Read them in this order.
1. The sample. What the customer submitted, usually a compound name and a quantity, sometimes a batch or lot reference. This is the lab’s record of what it was told the sample was.
2. The identity result. Usually mass spectrometry. The lab measures the molecular mass of what is in the vial and compares it against the theoretical mass of the compound it is supposed to be. If the observed mass matches, the compound is what it claims to be. If a certificate has no identity test, nothing on it confirms the vial contains the right molecule.
3. The purity result. Usually reversed-phase HPLC. The instrument separates everything in the sample and measures how much of the total signal belongs to the main peak. A result of 99.2% means the main peak accounts for 99.2% of the signal detected, with the rest being related impurities. It is a proportion, not a weight.
4. The quantity result. Some certificates also report how much peptide was found in the vial against what the label says. This is a separate measurement from purity and it is the one most often missing.
5. The method and the date. Which technique was used, and when the test was run. A certificate with no date cannot be tied to a current batch.
Purity is not the same as peptide content
This is the most common misreading.
HPLC purity describes the share of the detected signal belonging to the target compound. Peptide content, sometimes called net peptide, describes how much of the powder in the vial is actually peptide. Synthetic peptides are supplied as salts and hold residual water and counterions, so a vial can be 99% pure by HPLC and still contain noticeably less peptide by weight than the label suggests.
Both numbers are legitimate. They answer different questions. A supplier publishing purity alone is not hiding anything, but a supplier publishing both is telling you more.
How to check a certificate is genuine
A certificate is a PDF or an image, and both are easy to alter. Three things make one checkable:
The laboratory is named. An unnamed “independent third-party lab” cannot be verified at all.
There is a test or report number. This is the laboratory’s own reference for the job. It is what lets anyone confirm the report exists.
The number can be checked with the laboratory. Janoshik Analytical, used widely in this sector, publishes results under a test number and a verification key, and newer reports carry a QR code that opens the same report on the laboratory’s own website. If the copy on a seller’s site and the copy on the laboratory’s site agree, the certificate has not been altered.
If a certificate carries no test number, it is not necessarily false. It simply cannot be independently checked, and it should be read as documentation the seller has rather than as verification.
Matching a certificate to the vial in front of you
A certificate describes one batch. The question that matters is whether it describes your batch.
That link is made by a batch or lot number that appears both on the certificate and on the vial. Where vials carry no batch identifier, the certificate still tells you the seller had a sample of that compound tested, but it cannot be tied to the specific vial you received. This is a common limitation across the sector, and it is worth asking any supplier about directly.
What a COA does not cover
A purity and identity certificate is silent on everything else, including:
- Sterility and endotoxin. These are separate tests and are rarely performed for research-grade material.
- Residual solvents, water content and heavy metals. Separate tests again.
- Stability over time. A certificate is a snapshot on the test date.
- Regulatory status. A certificate is not an approval, and “research use only” on a label does not change a product’s status under Australian law.
Red flags when reading a certificate
- No laboratory named, or a laboratory that cannot be found.
- No test or report number, and no way to verify with the lab.
- The same certificate reused across different batches or products.
- A purity figure with no method stated. 99% measured how?
- A batch number on the certificate that does not match the product.
- Purity presented only as a marketing claim on a product page, with no document behind it.
- A certificate presented alongside claims about treating, healing or dosing anything. That tells you something about the seller rather than the sample.
A worked example
Reading one of NuVion’s published certificates, for retatrutide:
| Field | What it says | What it tells you |
| Laboratory | Janoshik Analytical | Named, independent, checkable |
| Test number | 195038 | The lab’s own reference for the job |
| Purity | 99.22% by RP-HPLC | The main peak is 99.22% of the detected signal |
| Identity | Mass spectrometry | The compound is what it is labelled as |
| Date | 7 July 2026 | When the sample was analysed |
NuVion publishes every certificate it holds at certificates of analysis, and each product page links to the certificate for that compound. Eleven of those certificates were commissioned by NuVion directly. The rest were commissioned by the supplier, or are older NuVion reports published with some details omitted. The difference is worth knowing when you read any supplier’s library, including this one.
Frequently asked questions
What does 99% purity on a peptide COA mean?
It means the main peak accounted for 99% of the signal the instrument detected, usually by reversed-phase HPLC. It is a proportion of what was detected, not a statement about how much peptide is in the vial by weight.
Does a certificate of analysis mean a peptide is safe?
No. A COA reports purity and identity. It says nothing about safety, sterility or whether a product is approved for any use. In Australia these compounds are supplied as laboratory chemicals and are not approved therapeutic goods.
What is the difference between HPLC and mass spectrometry on a COA?
HPLC measures how pure the sample is. Mass spectrometry confirms the compound is the one named, by measuring its molecular mass. A complete certificate includes both.
How can I verify a peptide COA is real?
Look for the laboratory’s name and a test or report number, then check that number with the laboratory. Reports from Janoshik Analytical can be opened on the lab’s own site using the test number, and newer ones carry a QR code that does the same thing.
What should I do if a supplier will not show a certificate?
Treat it as missing information and decide accordingly. Published certificates that can be read before ordering are more informative than a certificate promised on request.
Research use only. The compounds discussed on this page are supplied as laboratory chemicals for in vitro research. They are not therapeutic goods, are not approved by the Therapeutic Goods Administration, and are not for human or veterinary use. This page explains how laboratory documentation is read. It is not medical, legal or regulatory advice.