Research Notes
Published 8 August 2026 · Obsidian BioTech Research Team
"Third-party purity verified" appears on most research peptide product pages, including ours, but the phrase gets used loosely across the industry. Some suppliers use it to mean an in-house test; others mean a genuine independent lab report. Here's what it actually involves, and what to check for when a Certificate of Analysis (COA) is provided.
A Certificate of Analysis is a document produced by an analytical laboratory reporting the measured composition of a specific batch — not a product line in general, but the exact lot that shipped. A meaningful COA states the testing method used, the purity percentage measured, the batch/lot number it corresponds to, and the date of testing. A COA without a batch number tells you almost nothing, since there's no way to confirm it corresponds to the product actually in hand.
High-Performance Liquid Chromatography (HPLC) separates a sample into its individual chemical components based on how they interact with a column under pressure. The output is a chromatogram — a series of peaks, each representing a distinct compound in the sample. The target peptide should produce one dominant peak; the area of that peak relative to all other peaks gives the purity percentage. Smaller peaks indicate synthesis by-products, degradation products or incomplete peptide sequences — common artefacts of the peptide synthesis process that a purity test is specifically designed to catch.
HPLC tells you how pure a sample is, but not definitively what it is. Mass spectrometry (MS) measures the mass-to-charge ratio of ionised molecules in the sample, which is compared against the expected molecular weight of the target peptide. This is the step that confirms identity — that the compound in the vial is actually the peptide it's labelled as, not a structurally similar but incorrect sequence. Reputable suppliers run both HPLC and MS together, since purity and identity are separate questions and neither test alone answers both.
Every batch we supply is tested by an independent third-party laboratory to >99% purity by HPLC, with mass spectrometry confirmation of identity. Certificates of Analysis are available on request for any product — see our sourcing standards for more detail on how we vet manufacturers.
Research Use Only
This article is provided for general informational purposes. It is not a substitute for reviewing the specific COA and documentation provided with any product. None of the compounds sold by Obsidian BioTech have been approved by the MHRA, FDA or any regulatory body for human or veterinary use.