You can feel the gap the moment a page says tested and then offers you a badge instead of a file. Evaluating testing means reading the paperwork, checking who produced it, and matching it to a batch. A badge that says "tested" is a claim until the report is in front of you.
Separate the claim from the report
Treat website copy as a claim. Treat a full laboratory report as something you can inspect. Useful reports usually include:
- The laboratory's name
- A report or sample identifier
- The date of the test
- The method used
- The identity of the material tested
- The lot or batch the sample came from
- The result, with units
If a page says "third-party tested" and the only file is an undated image with no laboratory name, you do not yet have a third-party report. Notice that before the percentage gets your attention.
What third party should mean
Third party means a laboratory that is not the seller and is not owned by the seller. An in-house document and an outside document answer different questions. In-house testing can still be real testing. It is just not independent.
Weaker signals:
- A stock photo of a laboratory
- A badge that says tested, with no report
- A purity percentage with no method
- One old report applied to every product in a catalog
- A laboratory name you cannot connect to an actual laboratory
Stronger signals:
- A batch-specific report
- A method you can name
- A laboratory identity you can check
- A lot number you can match to the container
- More than a single summary percentage, when the report includes the underlying result
Pair this checklist with how to read a certificate of analysis.
Purity claims
A purity claim is a sentence about a number. Without the report, you cannot tell whether the number is area percent, a quantitative assay, a specification, or a marketing target. When you do have a report, read the method line beside the number. Compare that method across suppliers only when the methods are actually the same. Different methods do not produce interchangeable percentages.
PeptideRank's supplier directory does not publish purity figures. A percentage on this site would be a measurement only if a report you can open defined it.
Affiliate links are not test results
PeptideRank may earn a commission if you follow an affiliate link. A commission does not verify a laboratory, a batch, or a product. Discount codes give a discount. Affiliate links are marked and use rel="sponsored". Read the affiliate disclosure. Sponsorship is not a testing result.
A short checklist
- Is there a report, or only a claim?
- Is the laboratory named, and is it separate from the seller?
- Does the lot on the report match the lot on the container?
- Are the method and the date visible?
- Is the purity figure defined by that method?
- Are you looking at this batch, or a file reused from another one?
If the documents do not answer these questions, the honest status is "not established."
The volume side of a labeled vial is separate from paperwork. Reconstitution math explains that calculation, still without suggesting an amount.