Independent side-by-side comparison of HK Peptides and Peptides 4 Research — third-party lab grades, tested purity, COA availability, FDA warnings, and community ratings.
Bottom line: HK Peptides holds the stronger independent lab grade (C vs D); Peptides 4 Research shows higher average tested purity (99.5% vs 98.7%); HK Peptides has more published third-party tests (5 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.
HK Peptides: 5 independent Janoshik assays, across 5 substances, median measured purity 99.7%, most recent 2025-11-03. Peptides 4 Research: 2 independent Janoshik assays, across 2 substances, median measured purity 99.5%, most recent 2025-12-29.
| Attribute | HK Peptides | Peptides 4 Research |
|---|---|---|
| Independent lab grade | C | D |
| Third-party tests | 5 tests, avg purity 98.7% | 2 tests, avg purity 99.5% |
| COA available | No | No |
| Endotoxin tested | No | No |
| FDA warnings | None on record | None on record |
| Substance | HK Peptides | Peptides 4 Research |
|---|---|---|
| HGH 24 IU | 95.42% (1 assay, latest 2025-11-03) | Not tested |
| KPV 10mg | 99.79% (1 assay, latest 2025-04-09) | Not tested |
| Tirzepatide 30mg | 99.70% (1 assay, latest 2024-09-30) | Not tested |
| Tirzepatide 10mg | 99.70% (1 assay, latest 2024-09-30) | Not tested |
| Nad+ 500mg | purity not reported (1 assay, latest 2024-09-26) | Not tested |
| Cjc-1295 NO DAC 10MG | Not tested | 99.27% (1 assay, latest 2025-12-29) |
| Retatrutide 10mg | Not tested | 99.70% (1 assay, latest 2025-10-31) |
| Checked | HK Peptides | Peptides 4 Research |
|---|---|---|
| Certificates of analysis | None found on the site | Not stated |
| Products listed | 15 | Not stated |
| Ships to | United States, Europe, Worldwide | Not stated |
| Stated origin | China | Not stated |
HK Peptides. HK Peptides: 5 independent Janoshik assays, across 5 substances, median measured purity 99.7%, most recent 2025-11-03. 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.
We found no certificates of analysis anywhere on HK Peptides' 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.
HK Peptides states it ships to United States, Europe, Worldwide, and Peptides 4 Research does not state one. Both are read from the vendors' own sites.
Full profiles: HK Peptides, Peptides 4 Research.
Full lab-test records: All 5 HK Peptides lab tests, All 2 Peptides 4 Research lab tests.
Related comparisons: HK Peptides vs BioTech Peptides, Peptides 4 Research vs BioTech Peptides, HK Peptides vs Hangzhou Mandy Biotechnology, Peptides 4 Research vs Healthletic, HK Peptides vs LA Peptides, Peptides 4 Research vs LimitlessBioChem.