Ambrus et al. "Semaglutide 'Research Chemical' Analysis"
This is one entry from the TitrateLab Vendor Graveyard, a dated, primary-source archive of peptide-market shutdowns, exit scams, and enforcement actions. Documented as JMIR 2024. Sources for this entry are named inline below and numbered in full on the parent archive page.
Ambrus et al. published a separate analysis in JMIR Infodemiology in 2024, testing seven randomly-purchased samples of “research grade” semaglutide from online vendors. Measured purity ranged from 7.7%–14.37% against label claims of 99%. Endotoxin was detected in every sample. (Ambrus 2024, JMIR)
This paper is the single most-cited peer-reviewed primary source in the research-peptide literature. We reference it in nearly every article that touches GLP-1s.