Lot number & product identity

The header should state the product name, strength, and lot number — and that lot number must match the unit in your hand. This is the anchor of the whole document. If the lot field is generic, blank, or different from your vial, the certificate isn't tied to your product and tells you nothing about it.

Identity — "is it the right molecule?"

The identity result confirms the compound is what the label says, typically by comparing its chromatographic profile against a known reference standard. Identity answers a simple but critical question: is this actually the substance named on the label, and not a substitute?

Assay / concentration — "how much is in it?"

The assay reports the measured content — for example mg per mL for an oil-based injectable solution, or percentage of label claim for a tablet. This is where under-dosing or over-dosing shows up. A genuine assay is a measured value with units, not a round marketing number like "99%+ pure" with nothing behind it.

Impurities & appearance

A thorough certificate records related substances or impurities, and for sterile injectables may note appearance and clarity. These fields show the lab looked for what shouldn't be there — degradation products and contaminants — not just what should.

The method (HPLC)

Most identity and assay results are produced by HPLC — high-performance liquid chromatography, which separates a sample into its individual components so each can be measured. Naming the method matters: it shows the figure came from an instrument and a procedure, not from an assertion. KEIFEI batches are HPLC-tested by an independent laboratory.

Lab identity & signature

A real COA carries the testing laboratory's letterhead, an accreditation reference, a stamp, the analyst's signature, and a date. Crucially, it includes the lab's own contact details — because a certificate you can't trace back to its issuer isn't verifiable.

How to verify it

  • Match the lot number on the certificate to the lot number on your unit.
  • Check the test date and that a named method (e.g. HPLC) is stated.
  • Confirm the lab's letterhead, stamp, and signature are present.
  • Contact the lab using the details printed on the certificate — not a number supplied separately by the seller.

A COA is batch-specific. One certificate that is reused for "the product" and never changes between lots is a marketing document, not an analysis. Every KEIFEI batch is issued its own lot-matched certificate.