Independent side-by-side comparison of Cocer Peptides and Peptides 4 Research — third-party lab grades, tested purity, COA availability, FDA warnings, and community ratings.
Bottom line: Peptides 4 Research holds the stronger independent lab grade (ungraded vs D); Cocer Peptides has more published third-party tests (37 vs 2).
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.
Cocer Peptides: 37 independent Janoshik assays, across 30 substances, median measured purity 99.6%, most recent 2026-03-27. Peptides 4 Research: 2 independent Janoshik assays, across 2 substances, median measured purity 99.5%, most recent 2025-12-29.
| Attribute | Cocer Peptides | Peptides 4 Research |
|---|---|---|
| Independent lab grade | Not graded | D |
| Third-party tests | 37 tests, avg purity 99.6% | 2 tests, avg purity 99.5% |
| COA available | No | No |
| Endotoxin tested | No | No |
| FDA warnings | None on record | None on record |
| Substance | Cocer Peptides | Peptides 4 Research |
|---|---|---|
| Retatrutide 10mg | 99.31% (3 assays, latest 2026-02-05) | 99.70% (1 assay, latest 2025-10-31) |
| Tirzepatide 30mg | 99.76% (3 assays, latest 2026-01-16) | Not tested |
| Kisspeptin 10mg | 99.62% (2 assays, latest 2026-01-19) | Not tested |
| Epithalon 10mg | 99.34% (2 assays, latest 2026-01-07) | Not tested |
| Reta 20mg | 99.57% (2 assays, latest 2025-10-23) | Not tested |
| Tb 500 Farg 10mg | 99.90% (1 assay, latest 2026-03-27) | Not tested |
| Glow | purity not reported (1 assay, latest 2026-03-27) | Not tested |
| Tb/bp 30/30 | purity not reported (1 assay, latest 2026-03-27) | Not tested |
| Reta10mg | 99.73% (1 assay, latest 2026-03-18) | Not tested |
| Bpc 10mg | 99.79% (1 assay, latest 2026-03-18) | Not tested |
| Motsc 10mg | 99.44% (1 assay, latest 2026-03-18) | Not tested |
| AOD 5mg | 99.08% (1 assay, latest 2026-02-20) | Not tested |
| Checked | Cocer Peptides | Peptides 4 Research |
|---|---|---|
| Certificates of analysis | 20 published on the site | Not stated |
| Payment methods | Cryptocurrency, Credit Card | Not stated |
| Ships to | Worldwide | Not stated |
| Research-use-only notice | Published | Not stated |
| Stated origin | Hong Kong | Not stated |
Cocer Peptides. Cocer Peptides: 37 independent Janoshik assays, across 30 substances, median measured purity 99.6%, most recent 2026-03-27. Peptides 4 Research: 2 independent Janoshik assays, across 2 substances, median measured purity 99.5%, most recent 2025-12-29. These are third-party Janoshik assays published against the vendor, not the vendor's own certificates.
Retatrutide 10mg has been independently assayed for both. Cocer Peptides measured a median 99.31% across 3 assays; Peptides 4 Research measured 99.70% across 1. Purity reflects the lots actually tested, not every batch either vendor sells.
Cocer Peptides publishes 20 certificates of analysis on its own site, and we have not read Peptides 4 Research's site. A published COA is the vendor's own document; the assay figures elsewhere on this page are independent of it.
Cocer Peptides states it ships to Worldwide, and Peptides 4 Research does not state one. Both are read from the vendors' own sites.
Full profiles: Cocer Peptides, Peptides 4 Research.
Full lab-test records: All 37 Cocer Peptides lab tests, All 2 Peptides 4 Research lab tests.
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