Head-to-head comparisons of peptide suppliers, built from records rather than reviews. 192 vendor pairs are published here; 165 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, Limitless Life Nootropics vs Reta-Peptide, Peptide-S vs SwissChems, HK Peptides vs SSR Bio, LVLUp Health vs YH Peptide, Amino Asylum vs Purus Peptides, Licensed Peptides vs VPeptide, InfiniWell vs PeptiAtlas, Henan Sahe Peptide vs InfiniWell, Apex Peptides vs Polar Peptides, Diju Peptides Wellness and Co vs LA Peptides, Amino Asylum vs Bioslab, OmegAmino vs UWA Elite Peptides, Inno Peptides vs Maximum Peps, LA Peptides vs SwissChems, Purity Peptides vs YH Peptide, Bioslab vs InfiniWell, LA Peptides vs Peptide-S, Maximum Peps vs Peptide Gurus, Felix Health vs Hangzhou Qihang Xingcheng, CanLab Sciences vs Zhuoyan Peptides, Purus Peptides vs UWA Elite Peptides, Licensed Peptides vs Peptide-S, Peptide Gurus vs Peptide-S, Qingfuji Trading vs Zztai Peptide, ResearchChemHQ vs TeaHRT, Certified Peptides vs Zztai Peptide, Cocer Peptides vs Helix Labs, InfiniWell vs Zhuoyan Peptides, Bioslab vs Henan Sahe Peptide, Hangzhou Mandy Biotechnology vs SSR Bio, Licensed Peptides vs Ro, Bioslab vs Hongbai Technology, LimitlessBioChem vs Peptides 4 Research, Peptide Sciences vs VPeptide, Dalian Handom Chemicals HDC vs Henan Sahe Peptide, Felix Health vs Heman Peptide HM, Apex Peptides vs Hangzhou Qihang Xingcheng, Modern Aminos vs Ro.
Related: Full vendor directory, Independent lab tests, How we rate vendors.