HPLC separates peptide compounds based on their chemical properties, allowing researchers to identify and quantify impurities with high precision. Mass Spectrometry complements this by confirming the molecular weight of the synthesized peptide, verifying it matches the theoretical sequence. Together, these two methods form the backbone of any credible Certificate of Analysis (COA). Researchers should always request third-party COAs from accredited laboratories when sourcing peptide compounds. A purity threshold of ≥98% is considered the minimum standard for reliable in-vitro research. Compounds falling below this threshold introduce variables that can compromise experimental reproducibility and data integrity. For research use only.