Documentation before claims
The first thing to evaluate in a supplier is not the marketing copy but the documentation behind it. A claim of purity or quality only matters if it is backed by a per-lot certificate that names the laboratory and the method.
The pre-purchase checklist
Before ordering, confirm that the supplier provides, for each lot, the measurements that matter for reproducibility.
- Third-party testing from a named laboratory.
- A per-lot Certificate of Analysis, not a product-wide one.
- Batch traceability from vial label to certificate.
- Purity (HPLC) reported together with identity (mass spectrometry).
Red flags
Certain patterns reliably indicate weak documentation, regardless of how the site is worded.
- Recycled or generic COAs shared across different products.
- Missing or ambiguous lot linkage.
- Unnamed laboratory or no test date.
- Hype language substituting for measurements.
Why documentation beats marketing
A research result is only as reproducible as the material behind it. Documentation that ties a vial to a specific, tested batch is what lets you trust — and later audit — your own work.