Peptide Gurus vs Peptide-S — Vendor Comparison

Independent side-by-side comparison of Peptide Gurus and Peptide-S — third-party lab grades, tested purity, COA availability, FDA warnings, and community ratings.

Bottom line: Peptide-S holds the stronger independent lab grade (D vs C); Peptide Gurus has more published third-party tests (63 vs 0).

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.

Peptide Gurus: 63 independent Janoshik assays, across 58 substances, median measured purity 99.7%, most recent 2026-04-24. Peptide-S has no independent Janoshik assays on file.

AttributePeptide GurusPeptide-S
Independent lab gradeDC
Third-party tests63 tests, avg purity 99.5%None published
COA availableNoNo
Endotoxin testedNoNo
FDA warningsNone on recordNone on record

Measured purity, substance by substance

SubstancePeptide GurusPeptide-S
Retatrutide 10mg99.51% (3 assays, latest 2026-04-14)Not tested
Tirzepatide 30mg99.84% (3 assays, latest 2026-04-14)Not tested
Tirzepatide 10mg99.79% (2 assays, latest 2026-04-14)Not tested
Ss-31 40mg99.73% (1 assay, latest 2026-04-24)Not tested
Wolverine(bpc-157 5mg Blend With Tb-500 5mg)purity not reported (1 assay, latest 2026-04-23)Not tested
Wolverine(bpc-157 10mg Blend With Tb-500 10mg)purity not reported (1 assay, latest 2026-04-23)Not tested
Pinealon 20mg99.17% (1 assay, latest 2026-04-14)Not tested
Oxytocin 10mg97.53% (1 assay, latest 2026-04-14)Not tested
Hcg 10,000 IUpurity not reported (1 assay, latest 2026-04-14)Not tested
Pt-141 10mg99.90% (1 assay, latest 2026-04-14)Not tested
Tesamorelin 10mg99.74% (1 assay, latest 2026-04-14)Not tested
Retatrutide 5mg99.78% (1 assay, latest 2026-04-14)Not tested

What each site publishes

CheckedPeptide GurusPeptide-S
Certificates of analysisNot statedNone found on the site
Products listedNot stated186
Public pricingNot statedListed on the site
Ships toNot statedUnited States, Worldwide
CarriersNot statedUPS, USPS
Research-use-only noticeNot statedPublished

What we found on each site

Peptide-S

Frequently asked questions

Which has more independent lab testing, Peptide Gurus or Peptide-S?

Peptide Gurus. Peptide Gurus: 63 independent Janoshik assays, across 58 substances, median measured purity 99.7%, most recent 2026-04-24. Peptide-S has no independent Janoshik assays on file. These are third-party Janoshik assays published against the vendor, not the vendor's own certificates.

Do Peptide Gurus and Peptide-S publish certificates of analysis?

We have not read Peptide Gurus' site, and we found no certificates of analysis anywhere on Peptide-S' site. A published COA is the vendor's own document; the assay figures elsewhere on this page are independent of it.

Where do Peptide Gurus and Peptide-S ship?

Peptide Gurus does not state a shipping region, and Peptide-S states it ships to United States, Worldwide. Both are read from the vendors' own sites.

Full profiles: Peptide Gurus, Peptide-S.

Full lab-test records: All 63 Peptide Gurus lab tests.

Related comparisons: Peptide Gurus vs Amino Asylum, Peptide-S vs Amino Tech, Peptide Gurus vs Heman Peptide HM, Peptide-S vs Healthletic, Peptide Gurus vs LimitlessBioChem, Peptide-S vs LA Peptides.