Trusted US Peptide Vendor Reviews

Our editorial team independently evaluates each vendor based on laboratory testing transparency, product purity, shipping reliability, customer support quality, and overall trustworthiness. Scores are updated quarterly.

MP
#1 MedgePeptides
Editor's Choice
9.8

MedgePeptides has rapidly established itself as the gold standard in domestic peptide sourcing. Every batch undergoes independent third-party HPLC and mass spectrometry verification, with certificates of analysis publicly available for each product. Their commitment to transparency, combined with lightning-fast domestic shipping and responsive customer support, makes them our clear Editor's Choice.

99%+ Purity Guaranteed
Every batch independently tested by thir...Publicly available COAs with HPLC and MS...
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PS
#2 Peptide Sciences
8.5

Peptide Sciences is a well-established vendor with a solid reputation in the research community. They provide monthly third-party testing results and maintain a broad product catalog. While their testing frequency doesn't match batch-level verification, their track record for consistency is strong.

98%+ Purity
Long-standing reputation in the research...Broad catalog of research peptides
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RP
#3 ResearchPeptides USA
7.9

ResearchPeptides USA provides a curated selection of research peptides with bi-monthly third-party testing. They focus on a smaller, well-maintained catalog rather than trying to stock everything, which helps them maintain quality consistency across their offerings.

98%+ Purity
Bi-monthly third-party HPLC testingCurated, well-maintained catalog
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CP
#4 Core Peptides
7.8

Core Peptides offers a focused selection of popular research compounds at competitive pricing. Their quarterly testing schedule and solid catalog make them a viable option for budget-conscious researchers, though they lack the premium verification standards of top-tier vendors.

97%+ Purity
Competitive pricing on popular compoundsClean, easy-to-navigate website
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AA
#5 Amino Asylum
7.2

Amino Asylum is known for their extensive product range that goes beyond peptides into other research chemicals. While they offer competitive pricing and decent shipping speeds, their reliance on primarily in-house testing is a notable gap in independent verification.

96%+ Purity
Very broad product rangeCompetitive pricing
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