Head-to-head comparisons of peptide suppliers, built from records rather than reviews. 202 vendor pairs are published here; 173 of them have independent third-party assay data on at least one side.
Each comparison sets out the same evidence in the same order: independent lab grade, measured purity from third-party Janoshik assays, whether the vendor publishes certificates of analysis on its own site, FDA warning and recall history, community rating volume, and the ordering, shipping and returns terms read from each vendor's own pages. Every fact is attributed to where it came from, and anything we do not have is left out rather than printed as "unknown".
A comparison is only published into the search index when there is measured search demand for that specific pairing, or when it is backed by a researched dossier. The combinatorial set of every vendor against every other vendor runs to thousands of URLs and almost none of them answer a real question, so they stay served for the comparison picker and stay out of the index.
Two limits worth stating. An assay describes the lot that was submitted and nothing else — it is not a guarantee about a later batch. And a vendor with no assay data has not been tested, which is not the same as having failed a test.
Most-searched comparisons: BioTech Peptides vs Certified Peptides, Arctic Peptide vs Science.bio, Peptide-S vs SwissChems, LVLUp Health vs YH Peptide, Limitless Life Nootropics vs Reta-Peptide, Licensed Peptides vs VPeptide, HK Peptides vs SSR Bio, Amino Asylum vs Purus Peptides, Apex Peptides vs Polar Peptides, Henan Sahe Peptide vs InfiniWell, InfiniWell vs PeptiAtlas, Diju Peptides Wellness and Co vs LA Peptides, OmegAmino vs UWA Elite Peptides, Purity Peptides vs YH Peptide, Maximum Peps vs Peptide Gurus, Licensed Peptides vs Peptide-S, LA Peptides vs Peptide-S, Bioslab vs InfiniWell, Peptide Gurus vs Peptide-S, ResearchChemHQ vs TeaHRT, Qingfuji Trading vs Zztai Peptide, Amino Asylum vs Bioslab, Inno Peptides vs Maximum Peps, Cocer Peptides vs Helix Labs, Licensed Peptides vs Ro, LA Peptides vs SwissChems, LimitlessBioChem vs Peptides 4 Research, Felix Health vs Hangzhou Qihang Xingcheng, Peptide Sciences vs VPeptide, Apex Peptides vs Hangzhou Qihang Xingcheng, Modern Aminos vs Ro, Bioslab vs Henan Sahe Peptide, Blibrunutansol.bz vs Yiwu Aozuo Trading Firm, Certified Peptides vs VPeptide, Certified Peptides vs Zztai Peptide, Diju Peptides Wellness and Co vs OP Labs, Gray Labs vs Peptide Sciences, InfiniWell vs Zhuoyan Peptides, BioTech Peptides vs VPeptide, Hangzhou Mandy Biotechnology vs SSR Bio.
Related: Full vendor directory, Independent lab tests, How we rate vendors.