Independent side-by-side comparison of Gray Labs and Peptide Sciences — third-party lab grades, tested purity, COA availability, FDA warnings, and community ratings.
Bottom line: Peptide Sciences holds the stronger independent lab grade (ungraded vs C); Gray Labs has more published third-party tests (1 vs 0); Peptide Sciences carries more community reviews (1247).
Every figure below is either measured by an independent laboratory or read from the vendor's own website, and the source is named against it. PeptideAtlas is not affiliated with either vendor.
Gray Labs: 1 independent Janoshik assay, median measured purity 99.4%, most recent 2026-02-09. Peptide Sciences has no independent Janoshik assays on file.
| Attribute | Gray Labs | Peptide Sciences |
|---|---|---|
| Independent lab grade | Not graded | C |
| Third-party tests | 1 test, avg purity 99.4% | None published |
| Community rating | No reviews | 4.7/5 (1247 reviews) |
| COA available | No | Yes |
| Endotoxin tested | No | No |
| FDA warnings | None on record | None on record |
| Year established | Unknown | 1990 |
| Substance | Gray Labs | Peptide Sciences |
|---|---|---|
| 20mg Retatrutide | 99.41% (1 assay, latest 2026-02-09) | Not tested |
Gray Labs. Gray Labs: 1 independent Janoshik assay, median measured purity 99.4%, most recent 2026-02-09. Peptide Sciences has no independent Janoshik assays on file. These are third-party Janoshik assays published against the vendor, not the vendor's own certificates.
Full profiles: Gray Labs, Peptide Sciences.
Full lab-test records: All 1 Gray Labs lab test.
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