Quality Standards

Every research peptide we ship passes three independent tests at an ISO-certified third-party laboratory before it leaves our facility. Each shipped batch carries a Certificate of Analysis that ties the batch number on the vial to the specific test results performed on that batch.

What we test for

HPLC — Purity

High-Performance Liquid Chromatography is the analytical method that separates the target peptide from impurities and quantifies the relative amount of each. The result is a percentage purity number — 99.2%, 99.8%, etc. — that tells you what proportion of the material in the vial is the intended compound versus everything else.

We require ≥99% HPLC purity for any peptide to ship. Batches that fail to meet that threshold are not sold. The HPLC chromatogram for each batch is included on the Certificate of Analysis, so you can verify the testing was actually performed and that the result matches the claim.

Mass spectrometry — Identity

Mass spectrometry confirms that the molecule in the vial actually is what the label says it is. HPLC tells you how pure the sample is, but doesn't on its own confirm identity — a sample could be 99.9% pure and still be the wrong compound. Mass spec verifies the peptide's molecular weight and structural fingerprint matches the expected reference for that compound.

Together, HPLC and mass spec answer the two questions that matter for any research compound: how pure is it, and is it actually what we say it is.

Endotoxin testing

Bacterial endotoxin contamination can compromise research reliability even at small concentrations. We screen every batch using LAL (Limulus Amebocyte Lysate) assay, the standard endotoxin detection method for laboratory compounds. Endotoxin results are included on the Certificate of Analysis.

Batch-matched Certificates of Analysis

A Certificate of Analysis is only meaningful if it ties to the specific batch in your hand. A generic certificate that says "this peptide was tested at some point" is not the same as a batch-matched COA that documents the exact lot, the exact testing date, and the exact analyst.

Every shipped batch carries its own COA. The batch number printed on the vial label corresponds to a specific record. Until the lab finishes delivering PDFs to our document store for direct download, COAs are available on request — email nate@nexaralabsusa.com with the order reference and product, and we send the matching COA back within one business day.

What we do when a batch fails

Batches that don't meet the ≥99% purity threshold or that show identity, endotoxin, or stability anomalies are not sold. They are documented internally and discarded. We don't blend, dilute, or relabel. We don't sell remediated material as a different product. If a batch fails testing, the path forward is to test the next batch — not to find a creative way to ship the failed one.

This is the part of quality control that most peptide vendors don't talk about publicly. We're disclosing it because the entire trust premise of buying from us is that the testing means something — and the testing only means something if failed batches actually get rejected.

Reconstitution supplies

Bacteriostatic Water reconstitution supplies follow a different standard. They are USP-grade sterility, 0.9% benzyl alcohol multi-use vials. They are not subject to peptide-purity testing because they are aqueous reconstitution materials, not active compounds — but they are sterility-tested per pharmacopeial standards.

What we deliberately do not do

• We do not publish reconstitution calculators, syringe-unit converters, or dosing guides — these tools operationalize injection prep regardless of disclaimer language, and we keep that line clean.
• We do not make therapeutic, medical, or human-use claims about any product. Nothing on this site describes a peptide as treating, preventing, or modifying any condition.
• We do not name a specific testing partner publicly while our lab partnerships are in transition. The COA itself names the issuing laboratory; we do not currently put that name on marketing pages because the partner can change between batches.

Related

• Testing & COAs — what to look for in a Certificate of Analysis and how to read one
• Research Compliance — what research-use-only means in practice and what we do and do not sell
• Refund and reship policy — how we handle shipping issues, damaged vials, and lost packages