Short answer
Independent testing means a vial is sampled and sent to an outside laboratory with no stake in the result. The lab runs HPLC and mass spectrometry, then issues a signed report with sample and lot numbers. In-house testing cannot be verified the same way, because the seller controls every step.
Want to see the result of this process? See a published certificate.
What does "independent" mean for a laboratory?
An independent lab is a separate organization that does not own, make or sell the product it tests, and that issues the report under its own name. Its business is the accuracy of the measurement, not the sale.
Independence is about structure, not quality alone. A lab owned by the seller, or one that only returns the numbers the seller requests, is not independent however good its instruments are. Look for a named lab and, where available, its accreditation. ISO/IEC 17025 is the international standard for testing-laboratory competence, and accreditation bodies publish who holds it.
How is a sample chosen and sent?
Someone pulls a vial from a specific lot, records the lot number, seals and labels it, and ships it to the lab. The record of who pulled it and when is part of what makes the result meaningful.
The key point for a buyer: the sample represents the lot only if it was drawn from that lot. A report on a hand-picked or re-made sample proves nothing about the vials that ship.
We pull a vial from our own stock and send it to an accredited, independent laboratory. The lab runs HPLC and mass spectrometry and issues the certificate.
Read a published certificate
Our certificates are published in a public library. See our certificates of analysis.
What tests does the lab run?
For identity and purity, the standard pair is mass spectrometry and HPLC. Content (the milligrams of peptide present) is measured separately, and endotoxin and heavy-metal panels are optional extras.
| Test | Question | Reported as |
|---|---|---|
| Mass spectrometry | Is it the right molecule? | Expected and observed mass |
| HPLC | How pure is it? | Percent of peak area, chromatogram |
| Content | How much peptide is in the vial? | Labeled vs measured mg |
| Endotoxin (optional) | Is bacterial endotoxin present? | Result against a limit |
| Heavy metals (optional) | Are metal residues present? | Result per element |
Details on the first two are in HPLC vs mass spectrometry.
What happens between the lab receiving the sample and the report?
The lab logs the sample against its identifier, prepares it (typically dissolving a measured portion), and runs the instruments. An analyst reviews the chromatogram and spectrum, the results are checked against the lab's acceptance criteria, and the report is issued.
For a buyer, three details matter here. The sample identifier should survive from submission to report, so the result maps back to the vial that was sent. The method should be named, not just "HPLC". And the raw data (chromatogram, spectrum) should exist, even if only a summary is attached to the report. You can ask for it.
Who is on the report?
The report names the lab and carries the sample identifier, the lot, the test date, the methods, the results and a signature or authorization. The seller's name may appear as the submitter, which is normal. The lab's name must be there.
If the report shows no lab, or shows only a logo with no contact details, you cannot confirm it with the source. See how to read a peptide COA.
How is third-party testing different from in-house testing?
With third-party testing, the party who gains from a good result does not produce it. With in-house testing, the same company makes the product, runs the test and writes the report.
In-house testing is not worthless. Manufacturers do it for process control. But a buyer cannot check an in-house report against anything outside the seller, and cannot ask the lab to confirm it. That is the practical difference: an independent report can be confirmed with the lab that issued it.
Why do buyers struggle to get usable test documents?
Buyers evaluating suppliers meet the same problems: a report that names no lab, one report reused across products, or documents that appear only after the order is paid. Each makes it hard to judge a lot before committing.
We publish certificates in a public library with their sample number and lot, and a certificate issued in your company's name is available on any wholesale order.
Does one report cover every vial in a lot?
No. A report covers the sample the lab received. It supports a statement about the lot only to the extent that the sample was drawn from that lot and the lot is uniform. That is why the lot number on the report matters, and why a buyer should ask how often each lot is sampled and whether a new lot triggers a new report.
A report from last year on an earlier lot is not evidence about the vials you receive today. Check the test date against the lot you are buying.
What does testing cost and how long does it take?
It depends on the panel and the number of samples. Identity and purity by HPLC and MS is the base panel; content, endotoxin and heavy metals add to cost and turnaround. Turnaround also depends on the lab's queue and on shipping time for the sample.
We do not state prices or turnaround here. We can arrange testing of your own research material through our accredited laboratory partner; use the request form on the testing page.
Common questions
What does independent mean for a lab?
The lab is a separate organization with no ownership in, or financial stake in, the product it tests, and it issues the report under its own name.
How is a sample chosen and sent?
A vial is pulled from the lot, labeled with its lot number, and shipped to the lab with a record of who pulled it and when.
What tests does the lab run?
Typically HPLC for purity and mass spectrometry for identity. Content, endotoxin and heavy-metal panels are added when requested.
How is third-party testing different from in-house testing?
With in-house testing the seller runs and reports its own results. With third-party testing an outside lab produces the report under its own name.
Can the same process be used on material bought elsewhere?
Yes, labs can test any sample submitted. The report then covers only the sample that was sent.