Independent Testing Keeps Finding the Same Problem in Grey-Market Peptide Vials
Mass-spectrometry analyses of consumer-purchased research peptides continue to report under-dosing, incorrect sequences, and endotoxin contamination in a meaningful fraction of samples.
The recurring failure modes are consistent across surveys: actual peptide content well below label claim, truncated or scrambled sequences from poor synthesis or degradation, and bacterial endotoxin in preparations produced outside sterile facilities.
Certificates of analysis are the industry's stated safeguard, but a COA is only meaningful if it references the specific lot, names the testing laboratory, and can be independently verified. Reused or unattributed COAs are common.
For readers evaluating sellers, the practical checklist is narrow: lot-specific third-party HPLC and mass-spec results, endotoxin testing for injectable preparations, and a verifiable testing laboratory. Absent all three, purity claims are marketing.