Third-Party Tested Research Peptides: How NuRev Publishes a COA for Every Lot

A third-party test is run by a laboratory that is not the seller. The seller sends a sample from a lot; the laboratory analyzes it and issues a signed report under its own name and report number. That separation matters because a seller checking its own product has an obvious interest in the result.

For a research buyer, the practical test is simple: can you see the report, and does it name the lab and the lot? A supplier that only says “tested” without showing the document gives you nothing to check. NuRev publishes the reports themselves, with the laboratory’s name and the lot number on each one.

Purity by HPLC. The sample is separated on a chromatography column and the main peak is compared with everything else detected. Purity is the main peak’s share of the total. For blends such as GLOW or KLOW, the report lists each component; NuRev labels show the lowest component value. The figure for your lot is on its report. See HPLC testing for peptides for how to read a chromatogram.

Identity by LC-MS. Mass spectrometry measures the molecular mass of what is in the vial and confirms it matches the expected compound. Purity alone cannot do this: a sample can be very pure and still be the wrong molecule.

Net peptide content. Lyophilized peptides contain water and counter-ions (often acetate or TFA) as well as peptide. Net content reports how much of the labeled amount is peptide, which is the number to use when calculating concentrations. Most NuRev lot reports include it.

Endotoxins by LAL. Bacterial endotoxins are a common contaminant in biologically sensitive work. NuRev publishes LAL endotoxin reports as separate documents for many lots, listed next to the purity report for the same lot. Background is in our endotoxin testing guide.

1. Find the lot number printed on the vial label (shown as BATCH).
2. Scan the QR code on the label, or search the lot in the COA library. The QR code opens that lot’s reports on nurevpeptides.com.
3. Match the lot: the report must carry the same lot number as the vial. A report for a different lot says nothing about yours.
4. Check the laboratory and date: the testing lab and test date are printed on each report.
5. Read the results: purity percentage, identity confirmation, net content and, where listed, the endotoxin result.

For a section-by-section walkthrough, see how to read a peptide certificate of analysis.

A COA describes the sample the laboratory received from one lot on one date. It does not describe other lots, and it does not cover what happens to a vial after it leaves the supplier, such as heat exposure or how it was reconstituted. That is why NuRev ties every report to a lot number rather than to a product name, and why storage matters: see our peptide storage guide.

It is also worth knowing that independent results can differ slightly between laboratories and methods. A purity figure of 99.4% from one lab and 99.1% from another is normal variation, not a contradiction. Large differences, a missing identity result or a lot number that does not match are the warning signs.

• Reports are published, not available “on request” only
• Each report names the testing laboratory and carries its report number
• Reports are tied to lot numbers that appear on the vial
• Both purity (HPLC) and identity (mass spectrometry) are tested
• Net peptide content is reported, so concentrations can be calculated
• Endotoxin results are available for the lots that need them
• Products are sold for laboratory research use only, with clear storage information

More on evaluating suppliers is in how to choose a wholesale peptide supplier.

1. United States Pharmacopeia. General Chapter <85> Bacterial Endotoxins Test.
2. United States Pharmacopeia. General Chapter <621> Chromatography.
3. International Council for Harmonisation. ICH Q2(R2): Validation of Analytical Procedures. 2023.