FAQ
What should I look for in a peptide certificate of analysis?
Look for purity percentage above 98%, identity confirmation via HPLC or mass spectrometry, residual solvent levels within acceptable limits, microbial testing results, batch numbers matching your shipment, testing method details, calibration dates, and analyst signatures. If any of these sections are missing or vague, ask the supplier for clarification before purchasing.
How can I verify a supplier's third-party testing claims?
Ask for the name and contact information of the testing laboratory. You can verify whether the lab follows recognized standards by checking if they follow USP or EP pharmacopeia guidelines. Some labs display accreditation symbols on their reports. You can also contact the testing laboratory directly to confirm they performed the analysis on the cited batch.
Is a lower price ever acceptable for peptides?
Minor price variations are normal due to differences in overhead and production scale. However, prices significantly below market average often indicate shortcuts in synthesis, reduced testing frequency, or resale of low-quality material. When a deal looks too good to be true, it usually is. Prioritize consistency and documentation over savings.
Does manufacturer location affect peptide quality?
It can. Countries with stricter pharmaceutical manufacturing regulations tend to produce more consistent results because manufacturers must follow established quality standards. However, location alone does not guarantee quality. Always review the CoA and testing documentation regardless of where the supplier is based.
How often should I expect to receive updated CoAs from a supplier?
Each new batch should come with its own CoA. If you are purchasing the same peptide repeatedly, batch numbers should change and certificates should reflect recent testing dates. CoAs older than twelve months should prompt a question about whether the supplier has tested more current production runs.
