Precision Materials For Considered Research

Crux Peptides is a trusted U.S. supplier of high quality peptides. Our focus is simple: pure, tested, trusted, and affordable peptides. Every peptide is third party tested by an A2LA-accredited US lab to verify 99%+ purity. Our commitment to precision and transparency sets us apart. All products are for research use only and are not for human consumption. 

Yes. Every batch of Crux Peptide research compounds is third-party tested, and results are documented in a Certificate of Analysis (COA) specific to that lot. Purity data is verified before any batch is released for sale

Yes. Every order includes access to the COA matching the exact lot/batch number shipped, so you can verify purity and composition data for that specific unit — not a generic, site-wide COA.

Our research peptides are manufactured and tested to meet a minimum purity threshold verified by HPLC and/or mass spectrometry, as reflected in each batch’s COA. Exact purity percentages vary by product and lot and are listed on the corresponding COA.

Most peptides should be stored in a freezer (typically -20°C) prior to reconstitution to preserve stability, and protected from light and moisture. Specific storage guidance is included with each product and on its COA — always follow the handling instructions provided with your order.

Orders are packaged to protect compound integrity in transit, with cold-chain handling used where required. We ship via FedEx with tracking provided on every order.

Each product ships with its lot number identified, which corresponds to the batch-specific COA available for that item. If you can’t locate your COA, contact our support team with your order number and lot number.