Testing & Certificates of Analysis

If you've never read a peptide Certificate of Analysis before, this page walks through what each section means, what to look for, and how Nexara batch-matches every shipped order to a specific COA. The goal is to make verification simple — not arcane.

What a COA actually is

A Certificate of Analysis is a document issued by an analytical laboratory that records the test results performed on a specific batch of material. It's not a marketing claim, a product description, or a promise — it's a record of what tests were run, on what date, with what equipment, by what laboratory, and what the results were.

A COA is most useful when it ties to a specific batch. A generic certificate that says "this peptide is 99% pure" without reference to a batch number is essentially marketing copy. A batch-matched COA that documents lot ABC-123 tested on a specific date by a specific analyst is verifiable evidence.

What to look for on a COA

Identity confirmation

A real COA confirms that the molecule in the vial actually matches what the label claims. This is usually done with mass spectrometry — the document should show the observed molecular weight (or an equivalent identifier) and compare it to the theoretical value for that compound. If those numbers match within tolerance, identity is confirmed.

Purity by HPLC

High-Performance Liquid Chromatography produces a chromatogram — a plot of peaks where each peak represents a separated compound. The target peptide is the largest peak; smaller peaks are impurities. The COA should show the chromatogram itself (so you can verify the test was actually run, not just summarized) and the calculated purity percentage.

Anything below 95% should raise questions. Most reputable suppliers ship ≥98% purity. Nexara's threshold is ≥99% — batches under that don't ship.

Endotoxin

Endotoxin contamination is measured by LAL (Limulus Amebocyte Lysate) assay. The COA should report the result either as a numeric endotoxin unit (EU/mg) or as a pass/fail against a defined threshold. Endotoxin testing is standard for any peptide intended for laboratory research.

Issuing laboratory

Every legitimate COA names the laboratory that issued it, with contact information sufficient to verify the document is real. If a "COA" has no laboratory letterhead, no analyst signature or initials, and no way to call the lab and confirm the document — it is not an actual COA. It is a marketing graphic.

Date and batch number

The COA should reference a specific batch (or lot) number that matches the printed label on the vial in your hand, and a testing date that is recent relative to your purchase. A 2018 COA on a 2026 shipment is a red flag — it likely means the document refers to a long-since-exhausted batch.

How Nexara matches batches to COAs

Every shipped batch is tested before it ships. The batch number that appears on the vial label corresponds to a specific COA record in our system. When you request a COA, we look up the batch number from your order, pull the matching COA, and email it back.

Today the COA delivery is on-request via email — send your order reference and product to nate@nexaralabsusa.com and we send the matching document back within one business day. We're working toward direct PDF download from each product page; that infrastructure is being added as our lab partners deliver electronic copies in a consistent format.

What we don't do

• We don't issue "blanket" COAs that apply to multiple batches. Every shipped lot gets its own document.
• We don't edit, retouch, or summarize COAs into marketing copy. The document you get is the document the lab issued.
• We don't ship batches that fail testing. They're documented internally and discarded.

Related

• Quality Standards — the testing methodology in detail
• Research Compliance — what we sell and what we deliberately do not
• About Nexara Labs USA — who we are and how we got here