How to Read a Certificate of Analysis

What a Certificate of Analysis Shows

A CoA is a lab report, not a marketing document — it's issued directly by the testing lab, in this case Janoshik, and covers a single, specific batch. The fields that matter most are:

• Sample & Manufacturer — identifies what was tested and who supplied it.
• Batch — the specific production batch this result applies to. A CoA never applies to a product generally, only to the batch named on it.
• Results — the measured content (in mg) and purity (as a percentage) of the target compound, sometimes as a single figure and sometimes as several values if multiple vials were tested.
• Analysis conducted — the date testing was completed, alongside the lab's signature.
• Unique verification key — a code that lets anyone independently confirm the result on the lab's own website.

Purity vs. Content: What's the Difference

Purity is a percentage — it describes what proportion of the tested sample is actually the intended compound, as opposed to residual solvents, degradation products, or other impurities, and is typically measured by HPLC (high-performance liquid chromatography). Content is a mass measurement, usually in milligrams — it's how much of the compound the lab actually found in the vial, which can run slightly above or below a product's labeled size. Both numbers matter, and neither one substitutes for the other: a high purity percentage says nothing about how much total material is in the vial, and vice versa.

Why the Batch Number Matters

Peptide production happens in discrete batches, and purity can vary slightly from one batch to the next even for the same product. That's why every CoA we publish is tied to a specific batch number, and why the batch shown on a product page is updated whenever a new batch goes into stock. A certificate from an old batch doesn't tell you anything reliable about the batch currently being shipped, which is why we always keep the published certificate current.

How to Independently Verify a Result

Every certificate we publish includes a unique verification key. To check it yourself, go to janoshik.com/verify and enter that key — the result comes back directly from Janoshik's own records, not from anything hosted on our site, so there's no need to take our word for it. You can see this in practice on any product page: for example, BPC-157's certificate includes its own verification key in the same place.