Independent side-by-side comparison of Gray Labs and Zhuoyan Peptides — third-party lab grades, tested purity, COA availability, FDA warnings, and community ratings.
Bottom line: Zhuoyan Peptides shows higher average tested purity (99.7% vs 99.4%); Zhuoyan Peptides has more published third-party tests (4 vs 1).
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. Zhuoyan Peptides: 4 independent Janoshik assays, across 4 substances, median measured purity 99.7%, most recent 2026-03-24.
| Attribute | Gray Labs | Zhuoyan Peptides |
|---|---|---|
| Third-party tests | 1 test, avg purity 99.4% | 4 tests, avg purity 99.7% |
| COA available | No | No |
| Endotoxin tested | No | No |
| FDA warnings | None on record | None on record |
| Substance | Gray Labs | Zhuoyan Peptides |
|---|---|---|
| 20mg Retatrutide | 99.41% (1 assay, latest 2026-02-09) | Not tested |
| Bb10(bpc 5mg + TB 5mg) | Not tested | purity not reported (1 assay, latest 2026-03-24) |
| Ss-31 10mg | Not tested | 99.69% (1 assay, latest 2025-06-16) |
| Epitalon 10mg | Not tested | 99.54% (1 assay, latest 2025-06-16) |
| Tirzepatide 10mg | Not tested | 99.80% (1 assay, latest 2025-03-06) |
| Checked | Gray Labs | Zhuoyan Peptides |
|---|---|---|
| Certificates of analysis | Not stated | None found on the site |
| Products listed | Not stated | 20 |
| Ships to | Not stated | Worldwide |
| Stated origin | Not stated | China |
Zhuoyan Peptides. Gray Labs: 1 independent Janoshik assay, median measured purity 99.4%, most recent 2026-02-09. Zhuoyan Peptides: 4 independent Janoshik assays, across 4 substances, median measured purity 99.7%, most recent 2026-03-24. These are third-party Janoshik assays published against the vendor, not the vendor's own certificates.
We have not read Gray Labs' site, and we found no certificates of analysis anywhere on Zhuoyan Peptides' site. A published COA is the vendor's own document; the assay figures elsewhere on this page are independent of it.
Gray Labs does not state a shipping region, and Zhuoyan Peptides states it ships to Worldwide. Both are read from the vendors' own sites.
Full profiles: Gray Labs, Zhuoyan Peptides.
Full lab-test records: All 1 Gray Labs lab test, All 4 Zhuoyan Peptides lab tests.
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