Standards

Why batch-level COAs, not representative ones

Jun 30, 2026 · 4 min read

A representative certificate describes a batch someone once made. It says nothing verifiable about the vial in your hand.

Infographic

What batch-level actually costs us

1:1 Lots to certificates One independent test per released lot, keyed to the vial's batch number
100% Shipped lots in the library If a batch is not searchable there, it did not ship
98.7-99.4% Observed purity range Across 2025 lots — published as it landed, not averaged

Testing every lot makes lot-to-lot variation visible. That is the point of it.


There is a meaningful difference between publishing a certificate of analysis and publishing the certificate for your batch.

## The representative COA problem

A supplier tests one lot, gets a good result, and posts that certificate against the product page indefinitely. Every subsequent lot inherits the reputation of a batch it has no relationship to. The document is real; its relevance to your vial is not.

## What batch-level means here

Every lot we release is tested independently and gets its own certificate, keyed to the batch number printed on the vial label. The COA library is searchable by that number. If a batch is not in the library, it did not ship.

## The uncomfortable implication

This approach makes variation visible. Purity moves between lots — 98.7% one batch, 99.4% the next. We would rather show that than publish one flattering number forever.

Research use only. Nothing here is medical advice or a claim of therapeutic benefit. PEPTiQX products are supplied for in-vitro laboratory research by qualified professionals.