FAQ
Frequently asked.
Everything you might want to know about the rankings, the rubric, and the editorial standard. If your question isn't here, email hello@vial-verdict.com.
About the rankings
- How are supplier scores calculated?
- Five categories with fixed weights: purity-data transparency (30%), Certificate of Analysis per lot (25%), shipping (15%), customer support (15%), refund policy (15%). The published methodology page lists the rubric for each score and exactly what evidence we look for.
- Can suppliers pay to change their scores?
- No. Suppliers cannot edit their scores — paid or otherwise. Vial Verdict earns affiliate commissions on some outbound links, but the commercial relationship has no effect on the score. The same supplier could refuse the affiliate relationship and the score would not change.
- How often are reviews refreshed?
- Every review carries a last-reviewed date at the top. Reviews are refreshed when documentation practice changes materially — new COA format, new lot tracking, changes to shipping or refund policy. We do not refresh reviews on a calendar; we refresh them when the underlying material changes.
- What does "Editor's Pick" mean?
- A small badge on the supplier that currently scores highest against the rubric. There is one Editor's Pick at a time. The pick is determined by aggregate score, not by negotiation.
About the methodology
- Why these five categories and not others?
- The categories reflect what actually breaks for research buyers, not what is easiest to evaluate. "Brand reputation," "social media presence," and "marketing aesthetics" are gameable signals; they are deliberately excluded. The five we score are the ones a procurement-careful buyer would care about.
- Why is purity data weighted highest at 30%?
- Because everything downstream — assay reproducibility, animal-model interpretation, reference-grade research conclusions — depends on whether the material is what the label says. Without per-lot HPLC + mass-spec, the lot is unverifiable. Higher weight reflects higher stakes.
- Do you ever lower a score after a supplier complains?
- Scores move in either direction when the underlying evidence moves. If a supplier improves their COA format or starts publishing chromatograms, the score goes up. We do not lower scores in response to complaints; we lower scores when the documentation practice degrades.
About this site
- Is Vial Verdict independent?
- Editorially independent. We earn affiliate commissions on some supplier links, disclosed on every page. We do not accept payment for reviews, do not accept gifted material in exchange for coverage, and do not allow suppliers to preview reviews before publication.
- Is this medical advice?
- No. Vial Verdict reviews suppliers of compounds intended for laboratory and educational research. Nothing on this site is medical advice. Compounds discussed are research reference standards, not approved drugs.
- Who writes the reviews?
- The Vial Verdict editorial team. Reviews follow the published methodology rather than individual reviewer opinion — two reviewers applying the same rubric to the same evidence should land at similar scores.