What we did
193 independently tested samples across 17 companies, each compared against the purity claim printed on its own label.
Methodology How these samples were obtained and tested
- The cohort is every specimen in the Institute testing database whose label claimed 98% purity or better.
- Each sample is judged against its own stated claim rather than a single site-wide threshold, so a product claiming 95% and one claiming 99.5% are held to what each actually promised.
- All samples were purchased anonymously at retail and transferred under chain-of-custody documentation.
- Purity was measured by reversed-phase HPLC with UV detection; a subset was cross-checked at a second laboratory.
- Claims were taken from the product page and any certificate of analysis supplied at or after purchase.
- Where a seller-supplied COA carried a lot number, we checked it against the lot printed on the vial received.
- Samples measuring below 95% were re-tested from a second lot at a different laboratory before publication.
| Company | Index Score™ | Samples | Avg. purity | Lowest result |
|---|---|---|---|---|
| Cascade Research Group | 35 | 7 | 76.1% | 57.8% |
| Northwind Telehealth | 84 | 6 | 90.7% | 58.2% |
| Helix Research Supply | 79 | 15 | 95.7% | 70.8% |
| Vector Peptide Supply | 70 | 8 | 97.1% | 96.4% |
| Quantum Peptide Group | 89 | 12 | 97.6% | 96.6% |
| Meridian Health Direct | 89 | 6 | 97.6% | 97% |
A COA is a document about a batch, not a product line
If the lot number on the certificate does not match the lot on the vial, the certificate tells you nothing about what you received. This is the most common documentation failure we find.
The gap is not analytical noise
A point of disagreement between laboratories is normal, which is why we allow 1.5 points before calling a shortfall. 7 samples missing their own claim by more than three points is not a tolerance question. It is a description of a different product.
Specimens behind this report
Each links to its full laboratory record, chromatograms, methodology, lot number and chain of custody.
Nearly every research peptide sold online carries a purity claim, and nearly every one of those claims is 98% or higher. Many sellers supply a certificate of analysis on request. Some publish one. The question this investigation asks is narrow and testable: when an independent laboratory measures these products, does the number on the certificate hold?
We pulled every sample in the Institute's testing database whose label claimed 98% purity or better, 193 specimens across 17 companies and dozens of compounds, and compared the measurement against the specific figure printed on that product, rather than against a single threshold of our own.
141 of 193 samples, or 73%, came in below their own stated claim. 7 (4%) missed by more than three percentage points. Mean measured purity across the set was 96.9%.
Some of that gap is legitimate and we want to say so clearly. Analytical methods differ, reference standards differ, and a point of disagreement between two competent laboratories running the same sample is unremarkable, which is why our verdicts allow a 1.5-point tolerance before calling a shortfall. The 7 samples that missed by more than three points are a different matter. A product certified at 99% that measures 57.8% is not a methodological disagreement. It is a different product from the one described.
The mechanism is mundane and worth naming, because it is the thing buyers most often misunderstand. A certificate of analysis is a document about a specific batch, produced at a specific time, usually by or for the manufacturer. When a seller supplies a generic COA, no lot number, no date, or a lot number that does not match the vial, the document is evidence about some material, somewhere, once. It is not evidence about the vial in your hand. This is the single most common documentation failure we encounter, and it is not always deliberate.
The pattern across companies is consistent with what we find everywhere: sellers that publish batch-specific documentation, name their laboratories and disclose their manufacturing partners measure closer to their claims than sellers that do not. Transparency is not a proxy for quality because transparent companies are virtuous. It is a proxy because a company willing to publish a lot-matched COA is a company that has one.
Our recommendation to buyers is unglamorous. Treat a seller-supplied COA as a starting point, not a conclusion. Check that the lot number on the document matches the vial. Check that the issuing laboratory exists and will confirm it ran the assay. And treat any purity claim without a matching, dated, lot-specific document as an unverified marketing statement, because that is what it is.
