Maximum Peps vs PepSynth Labs — Vendor Comparison

Independent side-by-side comparison of Maximum Peps and PepSynth Labs — third-party lab grades, tested purity, COA availability, FDA warnings, and community ratings.

Bottom line: Maximum Peps has more published third-party tests (1 vs 0); PepSynth Labs carries more community reviews (120).

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.

Maximum Peps: 1 independent Janoshik assay, median measured purity 99.7%, most recent 2026-01-28. PepSynth Labs has no independent Janoshik assays on file.

AttributeMaximum PepsPepSynth Labs
Third-party tests1 test, avg purity 99.7%None published
Community ratingNo reviews4/5 (120 reviews)
COA availableNoYes
Endotoxin testedNoNo
FDA warningsNone on recordNone on record
Production countryNot specifiedUnited States
Year establishedUnknown2022

Measured purity, substance by substance

SubstanceMaximum PepsPepSynth Labs
Glp-3rt 20mg99.71% (1 assay, latest 2026-01-28)Not tested

What each site publishes

CheckedMaximum PepsPepSynth Labs
Certificates of analysisNone found on the siteNone found on the site
Products listed6734
Public pricingListed on the siteListed on the site
Ships toNot statedUnited States, Worldwide
CarriersNot statedFedEx, USPS
Research-use-only noticePublishedPublished
Stated originNot statedUnited States

What we found on each site

Maximum Peps

PepSynth Labs

Frequently asked questions

Which has more independent lab testing, Maximum Peps or PepSynth Labs?

Maximum Peps. Maximum Peps: 1 independent Janoshik assay, median measured purity 99.7%, most recent 2026-01-28. PepSynth Labs has no independent Janoshik assays on file. These are third-party Janoshik assays published against the vendor, not the vendor's own certificates.

Do Maximum Peps and PepSynth Labs publish certificates of analysis?

We found no certificates of analysis anywhere on Maximum Peps' site, and we found no certificates of analysis anywhere on PepSynth Labs' site. A published COA is the vendor's own document; the assay figures elsewhere on this page are independent of it.

Where do Maximum Peps and PepSynth Labs ship?

Maximum Peps does not state a shipping region, and PepSynth Labs states it ships to United States, Worldwide. Both are read from the vendors' own sites.

Full profiles: Maximum Peps, PepSynth Labs.

Full lab-test records: All 1 Maximum Peps lab test.

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